So Diablo 3 has been out for some time now and I still see people are asking and searching to see if Diablo 3 has a monthly fee. Pre-release, nobody was really sure how the game was going to be sold due to mixed information given out by Blizzard. During this interview for example, Jay Wilson mentions that the game might have a subscription free in some regions. Skip to 1:20.
Many people have gotten used to the idea of shelling out money each month to play their favorite game like World of Warcraft, but know that Diablo 3 DOES NOT have a subscription free. Of course, this does not mean you won't spend anything on the game other than the initial purchase. In fact, the real money Auction House has the potential of costing you more than if the game had a subscription fee.
So in case you where still wondering if "Diablo 3 Monthly Fee" is real or just old news, now you have the answer. It is a one time purchase, unless you decide to go crazy on the real money Auction House..