Hiring developer is easy, but choosing best developer or team, well suited for your requirements and to know level of experience to acknowledge your project complexities is very important.
Location: I today's world location doesn't matter, if you hire remote developers, like Indianlancer.com offers to hire best remote developers.
Budget: All it depends on the project scope, if scope you looking is small scale, that can be achieved within $1000 - $2500, if you have big scope, than that may vary upon estimating it.
Qualities: You first look over previous work done and what were the feedback given by the clients on their project development. Because it defines how well the team has performed to deliver solution on business needs.
Case Studies As you go through case studies of various projects done, then you will come to know about requirements, challenges, solution & adoption, and the final outcome. This make more clear about company that you might be looking to hire.