Ummm...do you remember those Wile E. Coyote/Road Runner lunchboxes or Scooby-Doo thermoses, and other assorted ancillary cartoon products...
No? You say you threw them out. Well, friend, you just threw out hundreds, if not thousands of dollars.
There are people who show up at comic book conventions with items such as Sherwood's, and make small fortunes selling them.
When SBSP finishes its run and is taken off the air, that toilet seat will be worth much more than $600.
Edit: wait - did you pay $600 for that, or $60?