Black Market overcharges guild members
I know I was the one who originally suggested that joining the thieves' guild should have a downside. Thomas responded by having stores raise their prices when you join the guild. Yay!
I'm fine with that, but traditionally the black market gives a discount to guild members. In a recent p21 game joining the guild causes prices to about double. Maybe the guild discount is still in there, but the price increase overwhelms it.
Since the BM already overcharges everyone, I suggest that this store should be a sole exception to the anti-thief sentiment and revert to its original behavior.