There's 3 major tradeoffs you'll have to make in a technical project. If you need to build fast, you can pay more for developers or give up some features. If you want it done cheap, you can find a new developer or cut corners on design. If you want the best work, it can be expensive or need more of your time to manage.
We joke that clients can pick 2. The truth is that creating a high quality design and building it well does take a lot of time, and thus a lot of money. Different teams offer their specialties at different rates, creating a market of vendors for clients to choose from. These 3 things should be the major factors they look at when deciding who to work with.
Are they capable of producing good work, with a history of satisfied clients? What will the project cost, and how long will it take? What outcomes can be expected from completing the project?
Clients pick vendors based on who they know is available and how familiar they are with them. Satisfied clients are not spending their time shopping around for another vendor. When they do go looking, it's often because one or two of these things has become an issue. Understand your position in the market and where you provide value. Are they looking for someone cheaper, faster, or better?