How to make a limited quantity or limited time gamepass or developer product?

I want to add a gamepass or developer product into my game. I want to include the ability to buy coins for the in game shop. Prices will be fairly average but every now and again, I want to have a deal, maybe for an hour or so where you can purchase a particular coin pack for less than it usually is.

I also wanted to include the ability to purchase special accessories for the character which will either only be available for a day or only 50 or so will be going on sale (I know it’s a bit optimistic as I on release I don’t expect to have 50 players playing at any moment). I’d like to know how to alter a gamepass or developer product script to make sure that it goes off sale after a day bang on the dot or it goes off sale as soon as the 50th one is purchased.

Come to think of it, this is a bit like how the Roblox limiteds work...

Thanks!