Warning indicator/border for unstackable utility items in shop/quickbuy

Now that we have more UI in the shop it'd be great to prevent the age old issue of multiple heroes buying utility items that don't stack(Mek,Vlad's,etc..). It would be great if valve could implement a red border around utility items that have already been purchased/in a players quickbuy. The border wouldnt disable an item from being bought to prevent abuse from the quickbuy option of course and with not to many unstackable items at this point it hopefully wouldn't clutter the shop UI either.