I love the idea - but I wonder why the price? it does seem really low. At 19 bucks and hour pro rata, you are not storing up cash to get through the hours when you are not earning, like marketing, talking to clients, understanding what they want.
Unless the projects are carbon copies (in which case automate) this will never work. The context switching will kill any productivity. You can work in parallel by threes - one in sales funnel, one in development and one in maintenance mode. And that will be tough.
It did get me thinking though - really good luck.