Help on a trigger

Hello. I am trying to make a trigger so when someone types a hat message such as "buy item" The tiem spawns and it deducts cash. Now it works so the item spawns and it deducts cash. But they can still keep typing it even if they have 0 and still get the item. So if they have 10 gold it deducts 10 gold, but if they have 0 it deducts nothing and they still get the item. So what trigger or condition do I need so if they dont have a certain amount of money they wont get the item? Thanks for the help.

Condition: Integer Comparison: Player Property: Current Gold of triggering player is greater than or equal to cost of item.