DM Coin Suggestion

I think it would be a good addition to the DM Coin system if we were able to plus an item with a certain amount of coins. For instance you could charge 5 DM Coins to plus an item from +9 to +10 and charge 10 coins to plus an item from +10 to +11 and charge 15 to +12 and 20 to +13. I like the DM Coin system but I think this would make it even better then it already is.