I wonder why everyone thinks they can sell their game. Selling games in the casual market is extremely tough. First, the market is stuffed. Second, the games that make money, even if they look simple took hundreds of hours to make and over a year to playtest and perfect. Myself and two others are in the process of making a commercial Android game and cumulatively, by the end, all three of us will have put in at least 700 - 800 hundred hours. Just go to any mobile market and look at the top selling games � they are amazing. They all have great graphics, great music, great sound effects, and great programming.
Get the game finished before you start worrying about making money. Once you have a great, commercially worthy game you'll be able to monetize it. I'd also recommend waiting for families before you start.
Remember: simple looking Plants vs Zombies took three years to make.