I had a blasted bronze DSM and enchanted it up to almost +10 and it still wouldn't sell. It seems to me there should be some value to these armors. I am suggested that perhaps either a repair shop should be instituted, although I know that would be a pain in the ass, or the shopkeepers offer 10% of the full value if it is enchanted past +0. So, if an armor sells for 45,000, then the shop owner will over 4,500. A 10th of the value. Of course, this really isn't that important in the scheme of things, just an idea.
I would some day like to see an artificer class, one that can select a specialty like swords or armor or rings, etc... For instance, depending on level they can increase to hit and to dmg, and later on add a brand. You could even employ the existing runes in this as materials for branding. So, those rods of nothing, rings of nothing, etc. Could be collected and enchanted. They could also recharge. An Artificer specializing in armor could repair and enchant armor and brand it. I think each brand would increase the cost. For instance, if an artificer has added fire brand to an armor which gives it fire resistance and they want to add acid, it should cost twice as much. Or the artificer can drain existing items and transfer brands. Like I said, just an idea.