Been thinking about an item to give your friends some help at a cost.
Rod of Exchange and Sacrifice
Wondrous item, rare
This obsidian rod has a series of arrows that point to both sides carved into it. Two characters can hold the rod and choose to either trade up to two different ability score points or one character can give up to two ability score points to a different character as an action. The trade must be voluntary, but outside factors can influence the characters. Two characters can only trade or give two ability points once or they can choose to trade the points back and rest the trade allowing for a different trade to take place.