Psst! Hey kid, wanna buy some paint?

So I've begun the process of painting my new apartment! I selected an awesome color for my hallway and main room (it's Behr's Pyramid Gold, and I would link to it but Behr's website sucks). But of course, nothing is ever easy when it comes to me. I got all self-conscious when the stupid know-it-all guy at the Home Depot paint counter put me on the spot in front of a bunch of other customers:

Jerk: What kind of finish?
Me: Uhhh, I don't know.
Jerk: (disbelieveing snort) You don't know?!
Me: It's for indoors.
Jerk: Fine. Then you want eggshell.
Me: Whatever.
Jerk: How much?
Me: Oh. Uh...
Jerk: Sweet Christ I don't have all day! HOW MANY FUCKING GALLONS?!!
Me: FOUR. Uhh, yeah. I need four.

So now I have four gallons of Pyramid Gold paint, and I barely need one and a half gallons. Wtf am I going to do with all this excess paint? Sell it out of my trenchcoat on a street corner?!