Ways of selling individual objects in game?

Say I have an ingame store but I don't have any ingame currency. In store, I would want to sell things like:

1. A Walk Animation
2. B Walk Animation
3. C Walk Animation
4. A Gun
5. B Gun ...The list could go on for hundreds of objects.

One way I have thought of is having an ingame currency, use that to buy things in-game, and then buy ingame currency using Robux. Then I would just save their in-game currency points in a datastore.

But if I were to directly sell using Robux, would each item have their own GamePass, and from there I would check if a player has that respective GamePass to unlock the thing? Or is there another way of doing so?

I scanned through different popular Roblox games and most of them has minimal Game Passes. I think each item having their own Game Pass is overkill and that there might be a more efficient way I am not aware of?