Don't know much about how this type of market works, but if Apple got one thing right was the $1 per app prototype. Unlike anything M$, no I'm not a Macfanboy, I'm a PC, where everything done down to the developers is about money. Yes Apple is about money to, but they got the app store right from the beginning. Make it affordable, this way if it's a bust you don't feel as cheated. Offer something fun, and cheap and then create a service around it and they will come.