MT gox charges a 1 % fee. Ripple is not going to be a successful exchange while XRP remains as expensive as it is now or unless it takes less ripples to perform an exchange then it does now. Maybe I am wrong but it looks like it is much more expensive when you factor all fees to exchange on Ripple as it is on the popular bitcoin exchanges.
Huh? Ripple transaction fees are negligible.
I thought you needed 200 xrp to send? That is currently more then $2 plus any exchange fees.