We've searched the internet and found the largest collection of On30 Scale trains for sale is on eBay. Below are the listings for 'gauge trains'.

On30 Narrow Gauge Locomotive Shed WITH SHOP Built Shay Climax Heisler Locos
On30 Narrow Gauge Locomotive Shed WITH SHOP Built Shay Climax Heisler Locos
$110.00
Time Remaining: 12d 13h 51m
Buy It Now for only: $110.00
On30 Narrow Gauge Fire Station Late 1800s Early 1900s Fire Station O Scale
On30 Narrow Gauge Fire Station Late 1800s Early 1900s Fire Station O Scale
$110.00
Time Remaining: 12d 14h 17m
Buy It Now for only: $110.00

Other On30 Scale train items recently purchased through this site:

On30 Narrow Gauge Fire Station Late 1800s Early 1900s Fire Station O Scale
On30 Narrow Gauge Locomotive Shed WITH SHOP Built Shay Climax Heisler Locos