there only such a prepaid plan that I know off but its only availabe for WoW China versions. over there you pay as you play. if wikipedia is correct, there is really cheap you pay $12.99 each month and can play up to 8 hours everyday estimate. So damn because I pay also $12.99 a month but only can play 4 hours max.

but since you are studying, i suggest you don't play wow. its addictive and will effect your studies (do it before its too late if you can't manage your time already) and unlike working where the worst case scenario only means you get sack and can start over in a new company easily....bad grades will be listed in your transcript forever and its really wasting time to change course or college to remove the bad grades and retaking too many times will waste time and money.

He said he is in California, so timing won't be a problem. Besides, there are lots of guilds that raids only on weekends. Can't expect top-of-the-line loot on a weekend only raid though.