General info - Upgrades?

I have an idea: feature which adds to the Cells Dungeon a possibility of upgrading all wearable items!

I'm thinking about adding stones / scrolls / potions that would be used to upgrade items (everything except from consumables). I haven't decided which one of these three names I would use, so let's call them 'IUs' (Item Upgrades) for now. There would be at lease 3 kinds of IUs:

• IU lvl1- damage / defence +10%
• IU lvl2- damage / defence +30%
• IU lvl3- damage / defence +50%

There would also be a possibility of combining two IUs in order to create another one with higher level. It would work only when one IU is lvl1.
Here's an example:

• IU lvl1 + IU lvl1 => IU lvl2
• IU lvl1 + IU lvl2 => IU lvl3
• IU lvl2 + IU lvl3 => ERROR!

Of course that's just an idea and I'm not at my PC now, so I'm not able to code or test anything : (
However, any thoughts about this addition are welcome!