There’s a bug when selling items and repairing.
Many times, after running an old instance and returning to Orgrimmar or Dornogal, when you sell the loot it only gives you 1c no matter what the actual item value is. Repairs also cost much more.
I’ve tested this several times today and it always happens. If you log out and back into the game, then you can sell everything at the normal price and repairs cost the normal amount. This happens both with and without addons (I tried disabling all of them and it still occurs).
As I said, I’ve checked this many times, with and without addons. I recorded a video (the interface is in Spanish) where you can see me selling two blue items from the Ragefire Chasm instance, and even though their value is much higher, the vendor only buys them for 1c, although I can buy them back for the same price.