OK. Having replayed most of the Mega Man Classic games at this point, I have to say I prefer when you find upgrades and items (like E Tanks) in the stages instead of buying them. I feel like when they're a finite resource the game is designed better around them. But when they're potentially infinite and you just need to grind the bolts to buy them, that slows down the games pace. Like, I played through all of Mega Man 9 and saved most of my bolts to buy E-Tanks before going to fight Wily. As a result I never had access to them. And now that I've gamed over at the Wily Capsule fight and don't have enough E-Tanks to buy more, I have to just go into other stages again and grind for more bolts so I can buy them (which isn't very fun).