That's not true of all collectibles. For the past two years I have made a very comfortable living reselling LEGO bricks and sets. I visit WalMarts, Targets, KMarts, etc twice a year when they are performing their resets. If you know the right people to talk to you can usually get them to take 50% off of all clearance toys if you agree to clean their shelves. Some sets are quick-flipped, some are stored away for 2-3 years until the sets retire and become more valuable. I also operate an online brick store that sells individual bricks to Adult Fans of LEGO (AFOLs) to use when building their individual models. It may sound silly, selling individual little bricks, but it is well worth the time and effort to sort and inventory well over 100,000 bricks.

The main thing is, it keeps me from having to get a real job.