The rumor is that SE will be dropping the absolute DISASTER known as VBV/MC securecard for FFXIV.
If that miracle of uncommonly good sense happens, any pre-paid credit card SHOULD work with the game.
Someone at one point even linked an overseas website that was selling pre-paid game time cards. . though whether or not this comes to pass remains to be seen.
I'm severely hoping that they drop VBV/MC secure card. I bought the FFXI collection a month ago for 10 bucks (cheaper than buying WotG and newer content that i missed after I quit during ToAU), and I STILL can't create an account because their secure card system is so borked.
Plus, I would think that S-E will definitely go the prepaid card method if they are trying to be open to more casual players. I would think it'd be in the same area as PSN's cards that are set at certain increments.