A few weeks ago...
For 50 cents!
*Sealed* copy of Pokemon Yellow: Special Pikachu Version, and, at the same sale...
For $1.00 more, I bought:
A "Berry"-colored GBC.
(I had to take out the batteries & their corrosion, clean it up a bit, put some new batteries in it...and it works just fine
This GBC had Pokemon Gold already in the system, and loose (carts only in clear, plastic cases) of Frogger & Tetris - all wrapped-up in a nice little, yellow, "Pikachu-themed" GBC-"Pouch" that looks like it probably came as part of a Yellow: Pikachu's Special Version bundle, or something.
About a month earlier, I found 10 PSX games @ $1.00/each (Including FF VII, VIII, IX, Legend of Dragoon, X-Files, Resident Evil: Director's Cut), etc.
I've probably been to ~100 or so worthless sales before I hit those 2 sales, though...