We've searched the internet and found the largest collection of On30 Scale trains for sale is on eBay. Below are the listings for '0 scale'.

On30 or 0 scale Logging Truck for diorama custom weathered lot 7
On30 or 0 scale Logging Truck for diorama custom weathered lot 7
$78.00
Time Remaining: 3d 16h 28m
Peco SL E596 Medium Radius Left Turnout Nickel Silver 0 165 NarrowOn30 Scale
Peco SL E596 Medium Radius Left Turnout Nickel Silver 0 165 NarrowOn30 Scale
$26.99
Time Remaining: 24d 20h 43m
Buy It Now for only: $26.99
Peco LK 555 Narrow Gauge Turntable Turn Table Nickel Silver 0 165 On30 Scale
Peco LK 555 Narrow Gauge Turntable Turn Table Nickel Silver 0 165 On30 Scale
$74.99
Time Remaining: 24d 20h 44m
Buy It Now for only: $74.99
Box of 12 Peco SL 500 Flexible 36 Flex Track 0 165 NarrowCode 100On30 Scale
Box of 12 Peco SL 500 Flexible 36 Flex Track 0 165 NarrowCode 100On30 Scale
$99.99
Time Remaining: 29d 22h 6m
Buy It Now for only: $99.99

Other On30 Scale train items recently purchased through this site:

On30 or 0 scale Logging Truck for diorama custom weathered lot 7
Peco LK 555 Narrow Gauge Turntable Turn Table Nickel Silver 0 165 On30 Scale
Peco SL E596 Medium Radius Left Turnout Nickel Silver 0 165 NarrowOn30 Scale
Box of 12 Peco SL 500 Flexible 36 Flex Track 0 165 NarrowCode 100On30 Scale