Buying upgrades for the team

[Empathy]

On my map, I want to allow the players to purchase upgrades for the computer on their team. The idea is an AoS, but you can upgrade the troops. Any suggestions on how I can implement a shop to sell the team an upgrade, that, when bought, will add a weapons upgrade to the computer on their team

 

[Slapshot136]

event - unit acquires an item
conditions - item type of item being manipulated is equal to upgrade
actions - 
if player # of (owner of triggering unit) is <7 then
set level of upgrade for player 1 to upgrade +1
else set level of upgrade for player 7 to upgrade+1

something like that?

 

[foodflare]

base the item off of something like a tome of power with no abils if you do slapshot's way but you should try his way