That's the reason why you get such good prices. Hire cheap developers and you have to take a gamble on the deliverables. If you're willing to pay a fair or premium price your worries decrease ;)
A good system would have a few "core people" who work together over a span of years on several successful projects. By a few, I mean 3-7.
If we can attract Bunnie Huang, all the better. :)