Dean's up by a couple hundred bucks which is, in his opinion, pretty damn good. So when he sees how Cas is doing, well. It's a miracle his eyes don't bug clean out of his head. That is...more than enough to keep them going for. God. A long time.

On the downside, it means people are starting to look at them a little funny, so Dean leans over Castiel's shoulder, patting his back. "C'mon, genius, let's get out of here before you clean out the house."

This isn't just contributing financially. This is a downpayment on a freaking house.