And the worst thing is that such "stamp" price is subject to speculation. Imagine that today you send a letter which costs you a quarter, but a month later you have to pay $10 because price is driven up by crazy traders.
AFAIK, now it's trading about $0.01 per 1 XRP. So, In posession of "founders" there are $200M worth of XRPs, and $500M to be given away to people who will probably start speculating it
P.S. I like the idea of ripple as a trading system, but XRP is really shitty thing.