I go through purges every few months and although it's a ton of work to sell and I usually don't break even, I'm just happy to find new homes for things. I really don't like the thought of trashing things, especially anime stuff that's hard to find. At first, I was clearing out extra items, but then I slowly started to go through my collections and I kept adding more and more to sell. Lots of things I thought I'd never let go I was ok with selling.
Eventually I hit the Truly Hard to Let Go Things. I took a long time figuring out if I really wanted to keep X item or if I was ok with selling, especially since I didn't really need to sell. People say it takes practice to let go of stuff easily, but it's still really hard for me to do!
On the funny side, I put all my sale photos in folders and it's interesting to look back and see all the stuff I've sold. It's a nice walk down memory lane.