How about a command where the first time you pick up an item or weapon, the pickup benefit is one thing, and after that, the benefit is something else? The easiest example is from Immoral Conduct, where the 1st time you pick up an Uzi, you get one, and the 2nd time, you get the dual Uzi weapon.
The command that I could think of would go something like this:
PICKUP_BENEFIT_FIRST=UZI9MM,BULLETS(32);
PICKUP_BENEFIT_SECOND=DUZI9MM,BULLETS(32);
It wouldn't even have to end at 2 definitions, potentially, as many as the modder wants could be used, with THIRD, FOURTH, FIFTH, etc.