Yeah...I don't understand the difference either! I had to put down a grand...that's a lot of $$ to part with when you're not sure whether it will go to good use or not!!
I guess they want to dissuade people from "accepting" a bunch of offers, only to give them up at the last minute (August), thus causing a scramble on the waitlist. But if med schools got around this problem, whey can't pharm schools? Boo.