Additionally I would think if a surfer is willing to sign up at $30 there's no doubt they are willing to rebill provided you are offering what you said you were offering and making sure you update regularly. Why would retention be so much better at $10, maybe slightly better but over time it will even out. People aren't buying at $10 because you've just presented them something so great they have to get their cards out, half of them are buying because it's cheap and they can cancel in a month if it sucks.
