It's actually very fine and cute that you cannot eternally repair an armor suit (only 6-7 times) and its overall repaired value will also decrease with time ongoing, meaning you wear it off. Same with weapons. But currently this has no effect on the selling price at the traders: I can sell a used suit at the same price than a new one, the price should drop according to the percentage of the object value, if the armor suit / weapon is at 10% lifetime, you should only get 10% of the normal selling price.