I don't think it's possible to balance all things on an item by item basis. However most of the old clothes have a 5-10 times higher TT value in general compared to all the new clothes. The cognac coat was just the example here, but it goes for almost all the old clothes.
Noone will buy a cognac even if the MU now has died to +20. They would rather buy a new coat with MU of +80. Since in that current MU, Cognac = 220, and new coat = 87.5. So even with 4 times higher markup on the item. The cost of the coat is still basically 1/3 of the cost of a cognac coat. This is an example of just how imbalanced the TT values are. Take a cognac at TT value, no MU. And the new coat is still less than half the total cost.
A TT reduction needs to be done on the old clothes. 50% or 70% or some value, across the board would be the easiest solution. Clothes could all be more uniform in the TT values, and it would open up a lot of markets and give all players more selection to customize their avatars.