I feel it would be like a giant XP bar that fills up so much per item, depending on the item donated of course, and increases by a multiplier similar to your character's XP bar. They could put in an npc in control of the entire thing which would show you a picture of the current progress done and remaining.


As far as effect on the game, I feel that putting items out of reach would be unfair for low populated servers, but making difficult to obtain items available by a different means after a certain stage would be balanced. Such as glamour versions of certain difficult to get armor sets and weapons, lvl 1 with no stat bonuses of course, higher level craftable items like jewelry or food being sold in shops that don't appear until a certain phase, and the such. This might be just what we need to tide us over for the next expansion, the community working together.