Mine isn't from an online purchase, but the ONE time I have found a decent thing to buy on Craigslist - it wasn't even really worth it... we had to drive 45 minutes (we at least made a day of it, hitting thrift stores and such along the way) - and I was just there to pick up a G3 pony in the box for $4. The lady also mentioned she had a "unicorn" for $0.50.
We meet her at a McDonald's in a random town, she's got the pony inside a Christmas gift bag thing, and so, we just give her $5 and call it good and head to the car. When we got to the car, I pulled the MIB pony out of the bag only to see that the pony, the "unicorn" she had for $0.50 was TAF Buttons in immaculate condition! I was really excited!
The worst thing... hrm... I pulled a pony out of a box from a lot I bought online and it had a bandaid stuck in it's hair...