I want to make in-game transactions to buy game coins.

I have a system on the island where random cases open every few minutes (they are free, as are the items that drop from them) and items are given out, but if the item that dropped has dropped before, in-game currency “Coins” is given out. But coins can be purchased for V-Bax in various amounts. Is it possible to sell for V-Bucks something that can be obtained for free over a longer period of time? This is implemented in many other games, even in Fortnite itself, where a small amount of V-Bucks can be obtained for free from the battle pass.