I'm looking for a seller entity script

Hello,

I'm looking for a seller entity script on which we can indicate the maximum number of entities that a player can buy.

This is very useful for my server because I don't use the classic f4 menu (darkrp) and I would like for example that the chemist can only buy 1 stove to cook his meth, but that he can buy 5 sulfuric acid.

Do you know a script that does this I will be very grateful for any information you can bring me.