I always see it as an decision: whats worth more, cash or time?
When you have lots of time but is low on cash, you can run one account and do all the things slowly (like building millions of gils for HQs, JP grind, lvling etc).
Later on life, you have less time but more cash. Then you can have extra accounts to accelerate your growth N times (being N the number of "slaves" that gonna do most of your job).
At my point, if i need to pay extra 13$ and bypass stuffs like cutting 1/N the time to farm certain amount of gil, or skipping out yells or partying events, then its still a good choice.
It just sucks all the commemorative content from FFXI tend to be time consuming, and all those mini lottos really adds up and kills most of my play time.
Don't ever go near an MMO with a cash shop!
I used to play FFRK, when i was at a point of spending same amount of FFXI subs money on gacha gacha content, that was the point i decided to quit (also because FFRK started to become a mindless grinding fest).