We are moving across country right now. We are going from a 1500 sq ft 4 bedroom house with a full basement and shed to a two bedroom 800 sq ft apartment with a 5x5 storage unit. We don't have much choice but to purge 50-75% of our stuff. It's been one of the greatest things I've ever done for myself. The focus it's allowed on the really important part of our lives is amazing.
We've sold well over $5000 of our stuff. We are fairly young so maybe our stuff is in general more desirable but if you work at you can sell a lot of stuff I think. That said we have also given away more than we sold. We put out a free sign and put it in the front yard and it went incredibly quickly.