Let's call it <$80 for RAM and a graphics card.
An SSD would be nice, but it's not necessary.
As for laptops, and I'll welcome the slings and arrows, I'd be hard pressed to recommend anything other than a Mac. I'm guessing that they aren't all this way, but every Windows laptop that I've ever used has been hotter and louder than s**t. My MB Air has the same processor as my PC laptop, but while the Air is dead silent and cool for almost everything that I do, the PC laptop has an annoying fan drone to it regardless of if I'm doing anything or not.
Want a dead silent (unless you're gaming), incredibly small, yet still powerful "desktop?" Get a Mac Mini. Heck, you can even put Windows on it. Get one with an SSD, and he'll be rockin'. Sure, it's integrated graphics only, but that's not horrible anymore (not awesome, but not horrible). I think that blows past your bang-for-the-buck, though. Way past.