It's pretty easy to get enough keys in a month to go for the 1050 rebate. 1050 keys, at 200 moon scrolls/key, cost 210.000 moon scrolls per month assuming you get 0 keys from anywhere else. That number is pretty easy to reach if you just log in and do dailies every day (from a certain level on. Keep in mind that leveling increases the amount of scrolls you get). I've gotten the rebate every month since month 2 or 3 of playing just by spending my moon scrolls.
You will have relatively little left over for other things from the groceries store, sure, but I am relatively sure keys (especially with the ultimate essence you get for the 21 pulls) are the most efficient thing to spend them on. The rest should likely go to bells/chimes, medium refine runes, or whatever situational powering/unlocking items you need (Experimental Vial, Summon Contract, or the outfit).
Log in in order to Post. LOGIN | Register
Confirm Delete Selected Topics?
Confirm Delete The post you selected?