I've Created a Monster!!!!

Yesterday, I spent a lot of time going through B's inventory of items to sell, doing more research, and posting some of the items on Ebay. I'm holding out hope for ebay, because Gas Monkey and I think this is her best option.
Rummaging around our stuff, I found the baseball/basketball cards that Gas Monkey thinks are worth something. So I started going through them, card by card. Most of them are only worth $1. I did manage to find one that seemed to be worth some money, but it isn't really selling well online.
Here's the monster situation. Let me just remind everybody, when Gas Monkey focuses on a project, it is nearly impossibly to draw him away from it. Gas Monkey came home. Let me just state, our focus right now should not be on selling baseball cards. We need to finish going through our stuff, and putting it into sell, give-away, or keep piles. However, when Gas Monkey came home, I foolishly told him I was having a hard time finding any cards of value. So the boy grabbed his collection, and starts pointing out cards.
"This one used to be worth $50, how much is it now?" he'd ask.
Dutifully, with extreme skepticism, I type in the card online. "$1."
"What?! What about this one? It's a David Robinson rookie card. That has to be worth a lot."
"Nope, $2."
We continued to play this game for an hour. Finally I gave up in exasperation. For the rest of the night, Gas Monkey enthusiastically searched his collection for cards that are still worth something. No luck. A few times the card has a lot of value, but everybody who has it is selling it for $2, unsuccessfully. It is really hard for Gas Monkey to accept that his collection, which he spent a very pretty penny on over time, has failed him. Poor boy. He's in denial.
The problem is, he is now temporarily obsessed with searching through his cards, when frankly, we have a lot of other stuff we need to do. His dad is coming down tomorrow. Our condo is a disaster. What to do, what to do? At least I know Gas Monkey will pull through at the last minute.