I'm thinking of something a little more full-service than that. There are a number of small contract dev shops that will do end-to-end product development. I've had fully designed apps churned out in as little as 6 weeks for under $50k, and they handled design, project management, QA, requirements gathering, etc.

The problem is that you have to find companies like this, and they tend to be small because the model doesn't scale past a certain point -- once you expand past a few teams, it becomes very difficult to control quality. Customers get upset and refuse to pay, which causes a cash flow problem. The best way to keep your accounts receivable aging down is to do quality work consistently, and the best way to have consistent quality is to keep your scale of control small.

This is not a business model that lends itself to VC well.