Selling my collections in the past due to debt has completely ruined the collecting of those systems for me. I had almost every SMS game (112 I think) and sold them. I had a monster of a Vic-20 collection. I also had a massive TG16 collection. Snes, Jaguar...quite a few. I made small attempts to re-collect them, but it just makes me sick to have to re-purchase games I already had, or not be able to find them again (or find them only in worse condition), as well as find them to be three times as much as I spent for them when I last collected.
That said, I can never collect those systems again (or so I feel at the moment). I took on a new mission I never did previously in the Genesis (never collected it) and now have about 1/3 of the entire set. I know the same thing would happen here should I ever sell, and I am going to try my damnest never to have to do that!