A quick, real-world anecdote: Walking through the Ferrari museum in Maranello to exit through the gift shop, you pass some small-scale die-cast ... race car models starting at $25.

Bidding starts as low as $11 for rare 1:18 and 1:24 scale die-cast cars. Models from manufacturers like AUTOart and Hot Wheels are included. It’s fun to write about rare and expensive cars sold ...