What if Steward+4 Copper is the same as being able to buy a Cache for $2?
I don't get it. Call me dense.
I you Steward for +$2 to buy a Gold, the opportunity cost is not trashing 2 Coppers, and a $2 buy. So if you trash 2 Coppers and buy a Cache (for $2), that's basically the same as if you +$2 and buy a Gold.
So I remember a good bit of discussion about what's the best Scout option in that scenario... it sounds like the argument here is that you obviously should take the Gold; because if Cache is balanced at $5, then it should be worth using your otherwise $2 turn to get the equivalent?
Of course, my counter-argument would be that going from 7 coppers to 9 coppers in your deck is not as big of a change as going from 7 coppers to 5 coppers. Percentage-wise, at least.