I had to go with try-before-you-buy model. With Micro-transactions and limited features, I feel like I am missing something and I pay up, but then I feel like I spent my money for nothing. Ad-supported games sound like a real pain because of all the, you guessed it, ads. And I just don't really understand Virtual currency, although I think I have used something similiar before. With try-before-you-buy, you get to taste everything, and if you don't like it, you aren't charged anything. And the only thing you are limited with is time.