I was really interested in the upgradeable buildings, not just for "challenge" but because it gives the game depth and feeds the player almost a story. But at least on the default normal settings the buildings cost way too much, and the early contracts just don't pay enough. Not only that but these contracts are essentially idiotic. I'm getting "survey random kerbal spot" missions before I have aircraft, before I can make manuever nodes (hell before I can even eva). And even if I can manage them, they don't pay beans. It just leads to grinding away at unfun and annoying contracts to get enough cash to build buildings. Instead of building rockets and doing cool space stuff (which I have the tech for), i'm struggling to upgrade the kerbal hotel so my kerbals can eva. Or i'm scrimping up change to upgrade the launchpad. Either buildings need tweaking, or the contracts. Probably both.