Cost wise if its cheaper to pay per month, lets say RM 20 I'd be willing to switch any day. Heck I'll even call all my old classmate from primary to uni to play and form guilds.
Primary deterrent from non MMORPG gamers is just the price needed to pay to play. They still have a strong stigma against it. But once they're hooked with the right game like WoW and the right price they're never going back.