Black Market is a promo anyway even though it's considered canon. We get to thank Isotropic for that.
So in my view it doesn't need "fixing" as you can decide how to set up the BM deck to your own liking.
What does need fixing is, in my view,
Scrying Pool.
+1 Action
Reveal the top card of your deck and either discard it or put it back.
Then reveal cards from the top of your deck until revealing one that isn't an Action.
Put all of your revealed cards into your hand.
So I just removed the "opponent-Spy" part as I think it's mighty strong without it and it makes it even more cumbersome to play. Usually you can play a couple of them in a row and it would be better if you're not hindering opponents more than necessary.