Stack with Cooldown

Hi,

I'm trying to let players purchase a stack of items with a cooldown after their purchase; however, I don't seem to be able to do so. I can either only let them purchase a single item and apply a cooldown afterwards or let them purchase a stack with no cooldown at all.

As an example: I'd like them to be able to purchase a stack of 25 ammo with a cooldown of X minutes to prevent them from purchasing larger quantities and recycling them for fast resources. As long as the ammo is listed in ItemCooldowns, I'll get the message "This item is cooldown restricted, you can buy only one"

Is that intentional, or am I missing something?

Thank you.