Here's my point: you can buy crafting/experience/other boosters for your character; you can temporarily advance faster with those. You can buy cosmetic items (which I have never done) like clothes or pets, none of which affect gameplay.or, you can buy extra bag slots, extra character slots, and treasure chest keys. It's also possible to unlock the full version of the game, which gives you some one-time bonuses, special items, and access to a summon skill that will soon be overshadowed. Finally, you can buy gold by exchanging your real-world investment for in-game currency. This literally allows you to buy the best equipment in the game.
Now, I appreciate te idea that a free-to-play game needs a means of making money from players who have already made the initial investment; I would ask youself what is really incentive enough;I'm glad the company resisted directly selling special equipment. Or am I? I mean, there's something that undermines gameplay when anything special about your character is purchased; the most disposable income wins. However, the alternative left me hungry for some incentive to having purchased the card. That hunger was partly satisfied. I unlocked the special edition, bought an extra character slot, an extra bag slot, and that was about it ( I got one of these for the holidays as well, in case you're noting that the price doesn't match). Was it worth it?
I've never usd the extra character slot--yet. Sure, I made a bunch of characters just to say I did, but I really only play 3 characters. The bag slot is great. Bags are expensive, in-game. This slot was the perfect solution for me. The extras are ok for the game, but you have to care how your character looks, how fast you level, or level your crafting. I once bought a key to one of the 30 black lion chests I had, but really, you're playing the lottery with that.
In conclusion, unless you can specifically identify what is of value to you in the game that you cannot achieve by other means, you will be disappointed that you did this. Keep in mind you are getting digital items in exchange for real money. Value, in that case, is in the eye of the beholder. Recommended with reservations.