Maker: Lionel Corporation 
Original Price: $5*
Worth Today: $250,000*

Pre-war Lionel Corporation trains will net you the most money. The Standard Gauge was an early type of toy train that Lionel invented in 1906. The train was a toy standard, not a scale modeling standard. The train ran on a triple-rail track. It’s possible Lionel created it on accident, misreading the Marklin European Gauge 2 instructions.

The trains were produced from 1906-1934, and five-hundred of these trains are thought to still exist today, which explains their high price at auction. The 1934 Lionel Standard Gauge Model Train Set is the most comprehensive of the Standard Gauge collections, and it was one of the last ones ever produced.