That's a pretty great thing about the android market - you can 'return' an app for a full refund.
For example, there might be 4-5 apps in the $30-50 range that I want to try. I'm not going to spend $150 and then having to request a refund for the rest - it simply won't happen.
I'd personally give priority to upgrade pricing and trials, but I'd still like to see Google Play's approach implemented by Apple here.