I used to have probably about 5-7 thousand comics, that I sold off in parts over the years. Usually when I thought I needed some extra cash for something. The biggest sells I had was a complete run of 100 issues of Nightwing I sold for 300 bucks, and a complete run of Deadpool, about 75 issues I sold for 400.
Then as I kept having kids, the room the comics were stored kept getting moved to a different room till finally they ended up in a closet. Eventually I came to the conclusion that I would never read those comics again, and if I wanted to, I could just easily download them, so I sold the rest for 450 bucks.
Now looking back, I wish I hadn't, I couldn't tell you what I spent the money on.
I wanna say that was a ton of comics, but I just sold 91 and barely put a dent in a single short-box. I probably at least as many as that (just judging by the size of 100 comics in one of my bags, I could put like 30 of them in my shelves).
Yeah, the money's a tricky thing. Figuring that I wouldn't ever read Nu52 Birds of Prey
or Huntress/Power Girl
again, I thought nothing of dropping them at a bookstore for like 22 bucks. Barely a drop in the bucket- two days' worth of food if you're on a budget.