Well, I can't answer your cost question but I can give you my two cents.
If you want to play PC games in the future, invest in a nice PC. If that is your main goal. I only wanted to play a few games, I upgraded to a good standard of Graphics Card, but noting special because I only really play FFXIV on it... and then there is internet and writing and storage. That's me. I have no need to spend $1000000 on a sweet PC if I'm only going to play 1 game. You have lasted this long without a PC for Sweet Gaming, do you really need to do it for one game?
I went for a and have and will always use the PS3 for gaming, for two main reasons. 1) Bluray for HD movies and 2) I love games and a lot of games I want are console only, better on console, or just because I want it in my console collection. Since I'm only a part time PC player, to me, it doesn't make sense to get an awesome PC. I admit, some games are awesome on the PC and if I had them hooked up to a sweet machine, my HDTV, and surround sound, I would be happy, but I will always go back to the console.
Id say decide what means more to you, then the input will help. I mean, there is no difference on PS3s but the HDD space, New Vs. Old, but HDD can be upgraded anyway. If you are inclined to a PC, then I can tell you 100%, people on here will put you in the right direction. I guess you could decide after you see the price tags on stuff though... but they are so different that if you decided PS3, what would be the point?
Regardless, FFXIV: ARR on the PS3 will not look as good as most PCs, period. You will need a keyboard, and you will lose the, teamspeak stuff, and 3rd party tools if the come around. Unless Sony EVER listens to us and allows cross chat for the PS3, but that would be limited to PS3 players only.
*Wint is also correct.
Edited, Feb 13th 2013 11:58am by WFOAssassin