If they told me it was $15 a month for one game, or maybe $18 a month for both, you better believe I would have gone for both games to play then.
I actually would love a sub option to just have both games for a flat (cheaper) fee, I mean let's face it ... xi is somewhat showing it's age a bit... but I would play it again if I could have both, I have quite a few friends that are either not on the xiv wagon yet... or on different xiv servers... but play xi still.
I was still play FFXI even after I played FFXIV but my PS2 was crapping out and the game was so unstable on the PS2. If the game was running fine, I probably wouldn't of given FFXIV a second look.
But saying that, I was happy when I came back to FFXIV for awhile just to see all the new stuff they added. But deep down with job systems, I like FFXI more.