As you know, I'm not a big fan of cash shops in MMOs. Even less in subscription games. But FFXIV has an interesting approach. One that I am not sure if I approve of or not.
It starts with holiday events. Unlike other MMOs, FFXIV's holiday events are completely new every year. For example, last New Year was a story about a group trying to introduce horses as a replacement for chocobos, which did not go over well with the citizens of Eorzea. This New Year was a story about weaponizing sheep to use in warfare.
(Yes, FFXIV holiday events are rather weird.)
The Holiday events feature a new quest and story line, as well as new rewards. For example, last year's Valentine's Day event had a special outfit as a reward. This year the reward is some rather snazzy chocobo barding (it has a top hat!).
What Square does is that after a holiday event is over, the rewards are then placed in the cash shop. So if you miss the event, you can buy the rewards for extra money.
Now, it's not like the rewards are hard to get. This isn't WoW where there's a 0.1% drop chance of getting the rare mount or pet from a holiday boss. If you do the Holiday Event story in FFXIV, you'll get all the rewards.
Is this a good and/or fair use of a cash shop in a subscription game? As much as I dislike cash shops with subs, these are time limited items. They're not particularly hard to get when the event is running. The reason you can't get those particular items in future events is because the future event is all new. That seems like a pretty reasonable balance to me.