The verification grid catches misidentifications before they become wrong prices
But when you see that getting 4 Energies is sort of a long draw, or, more importantly, you can quickly set up a quick offensive play using one or two Flame Patch cards, then Mega Charizard X EX can turn into a phenomenal sweeper
In these scenarios, your opponent cant strike back
If I've got Black Market out, those deaths will turn into mana on later turns
Obviously, you dont want to be sacrificing your best artifact or creature to Deadly Dispute, but if you sacrifice something small, its usually worth it
I do like that it doesnt count specifically instants or sorcery spells you cast, but rather any spell can count for the triggered ability and to satisfy the restriction for the activated ability