So.. let's imagine that "red-line" they currently have in place is removed (and, of course, the permanent durability loss). What you're essentially creating at that point (with this design) is a skill where more ability points spent = more savings via Repair.
Yes, just as more ability points spent into Loremaster also = more savings via Identify.
Obviously yes, the amount of gold you can acquire should be balanced, which is something that has to be done anyway.