What's it worth? - eBay item value calculator

Hi Folks,

great, that there is a board where you can present your own apps
I'd like to take this chance and present you my little project.
After presenting my app in the german forums, it's time for the english translation ;-)

I'm frequently selling stuff on eBay and every time before I do that, I search the completed items to find out what I will earn.
When I wanted to do this quickly on my phone I had to open the full web view of the eBay site, which is terribly slow and unusable on small devices.
So I always wanted to develop an app that does this for me with a simple user interface and only one click.

As soon as I got my Samsung Galaxy the development began

After weeks of work I finally got a working version of the "eValuator" or smoother "What's it worth?".

The app does exactly what you are doing, when searching in the completed items.

- You log in (you have to be logged in, to view the completed items)
- You enter some search terms
- You select a category to refine the search, because the search terms are ambigeous
- You select an item condition matching the item you want to sell
- You take a look at the prices and try to estimate an average price
- You ignore items that are described as defective or demaged

There you go: You know what you will probably earn

In my app you have it all with just one click:



Here you already see the median (mean value), which is more accurate than the simple average value, since it is not as strongly affected by single very low or high values.
If you want to read more on this -> Wikipedia (Median)
Below that you see the median including shipping, which is the real market value, or the value people are ready to pay for that item in total.
The last line shows the overall price range found.

Now you can restrict your search to a sub-category to get a more accurate result, or view the results in detail.



By clicking on one entry in this list you can open it in the android browser.


To handle the "ignore defective items" aspect, you can specify a permanent auto-filter, by entering the words you want to ignore in the settings.
All items containing these words in their title are from now on cropped from the search results and so no longer can affect the median value, making it more realistic.

Also you can specify how many items should be loaded with every search.
25, 50, 100 or 200
Doing so you can choose between faster loading and less traffic, or better and more accurate results based on a broader data set.

The app works for ebay.de ebay.com ebay.ch ebay.at and ebay.co.uk

ATTENTION:
Searching in completed items is only possible after logging in, so this app will need your eBay account.
I hereby promise, that this data is only used for the login and for nothing else.
It is not accessible to me or anyone else, it remains on your device and it is not sent anywhere.
Also it is stored in a secured memory area that is not accessible for other apps or via USB cable (see Android File API).
If anyone still is worried, I invite you to Dortmund (Germany) to go through the source-code with me ... free coffee included

The FREE version is available on the official market for free.
It is restricted to searches in Buy It Now items, but includes all features, so you can test everything before buying.

Here are the Links to both apps including the QR codes to the android market:
What's it worth?
What's it worth? FREE

I would appreciate constructive feedback of any kind!
The FREE Version is actively used by about 1000 users but only a few users left any feedback
And...of course...there are always some haters, just rating 1 star without any comment and not even giving a reason
Kind of frustrating to see your "baby" bashed just for fun as a developer
Funny to mention, that this is the case only for the free version...the full version got only 5 star ratings so far...leaves me with the conclusion, that there are people out there installing free apps just to destroy the ratings.

If you like it please leave a positive feedback on the android market! My further work depends on it!
THANK YOU!

Have fun using this app

Regards,
Rafael

— modified on Jan 21, 2011, 10:19:46 AM

I don't quite understand
You weren't able to make an eBay account, or you weren't able to login using my app?

This is the expected behavior :-)
The app loads the first page of results with a maximum of 200 items, according to the setting you made.
It reads the items and select only those, that were really sold (green price).
That's why it is not always necessarily a total of 200 items, that the average is calculated from, but the successfully sold items are the only items of interest.
It is not relevant for the current market value of an item if someone lists it for a price of 5000 but it never gets bought for that price.
Only what people are willing to pay for an item defines the market value.

If your query is specific enough (of course amp is not) this is a set of prices big enough to get a representative average price.
Loading all pages would take much more time, but would not improve the result from a mathematical point of view

Try a more specific search, like “iphone 3gs 16gb“.
amp delivers too many different amps from too many different brands in too many price classes, making an average price totally meaningless.
Just as the average price of all Smartphones would be. It wouldn't tell you anything on how much you might get, when selling for example a "Samsung i9000".

But if you want to sell for example the "iphone 3gs 16gb" mentioned above and search for that, then go to the appropriate sub category, to take items like cases for 1$ out of the equation you will get a really useful result.

Hope that explanation helps

— modified on Jan 27, 2011, 8:36:49 AM

I think the items are available for 3 month.

If the query is specific enough you don't need a big sample set to get a good result.
It doesn't really affect the value if you have a set of 1000 or 20 samples if they are all of equal or at least similar type.
The distribution for a specific item stays the same, so the average doesn't vary significantly.
To get a bigger sample set you would have to load several pages of the search result, each about 250 KB in size.
This would work on a stationary PC with DSL connection, but not on a mobile device, which has only 5KB/s in the worst case.
Even loading ONE page takes a long time then.

As I already said, amp is a really bad example.
The result you get has no meaning, because there are amps for home audio, there are amps for car audio, there are amps for 1$ and there are some for 10000$.
You get a number from the app, but it is completely meaningless. It doesn't tell you anything about the market value of ONE SPECIFIC model.
But when selling something and trying to estimate the possible profit, you have a specific amp with a specific name and model you can search for.
That would be an adequate test-case for the app, since it is made for exactly that purpose

Hi Jeremiah,

I'll think about that. When used in a WiFi network the loading of more the one pages shouldn't be a problem.
There are also some new features I am currently planning, that would probably benefit from a larger sample of items (especially auctions).

Greets,
Rafael

Hello Nick,

thanks for your great feedback!
Currently I have no plans of porting this app to iPhone, simply because it uses totally different technology and I would have to buy the hardware for development and testing (iPhone, MacBook). That's simply "not worth" the effort for me

But there is a (slightly complicated) way you can use the app on your PC. At least the free version.
The Android SDK contains an Android emulator on which you can install and run apps.

You should find a lot of tutorials on google by searching for: install apps on android emulator

Something like this http://www.botskool.com/geeks/how-install-apk-files-android-windows-sdk-emulator

Good luck!
Rafael

Great! The following should work best, once you have the emu running:

- Open the browser in the emulator
- Go to androidpit.com
- A prompt will appear asking you if you want to install the app center -> do it
- In the app center you can find and install the app

In this way you will also get all the future updates.

— modified on Aug 15, 2012, 11:39:37 AM

Hey guys!

For everyone who missed out on this app, because he had no Android device:
There is a totally new mobile website version: evaluator-online.com
Now the eValuator can be used, no matter what device you own.

Please note, that the site works well, but is still under construction.

Enjoy!