While a mini will technically run WoW, I wouldn't count on it being playable. The GMA950 is not meant for gaming in any way. I would do a quick search for Intel GMA 950 on the World of Warcraft forum and see what turns up.
As for paying $15 per month, I used to be in the same camp, but then I played the game through a free trial and loved it. I used to buy a new game about every month to month and a half. I have been playing WoW since November and have yet to purchase another game since. So since the I have spent $75 for 5 months(first month free) vs at least $150 I would have spent on other games. In the end, for alot of people, WoW actually saves you money.