You are confusing rationing with (essentially) gifting. Ration stamps merely represented a limited ability to buy a resource in short supply. For example, if

You are confusing rationing with (essentially) gifting. Ration stamps merely represented a limited ability to buy a resource in short supply. For example, if you had ration stamps for gasoline/petrol, you could buy up to whatever quantity you had stamps for -- you handed over the stamps and cash.