If you're finding round-screen color TVs in the trash, I'm gonna look into moving to VA. In NYC, a roundie is rare; and if one happens to pop up on Craigslist, the guy knows what he has and prices it accordingly.
It does, however, get to a point where we have so many old TVs and are running out of room for more... Been there. I drive, but don't make quite enough money to drive out to IL or WI or even really Boston to snag another set. Wish I could, but money's tight at the moment. In that case, even us TV-guys might not want it.
Once in a while, you'll come across a NICE Craigslist poster who just likes to see his equipment go to a good home.
Now, if I already have something I'm working on, I hate to dump it due to lack of time or whatever. I usually make the space for an interesting TV set or vintage stereo system even if it's not worth much or is worthless. Another thing to consider is sentimental value.... A few of my friends play guitar quite well, and find it tough to get rid of their dad's gear or guitar. After all, their dads were the people responsible for exposing their talent at a young age.
Just something to consider.