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

Roy C Link Industrial Narrow Gauge Handbook 7mm O 14 model railways RARE 
Roy C Link Industrial Narrow Gauge Handbook 7mm O 14 model railways RARE 
$73.07
Time Remaining: 4h 33m
16 LOG BRONC O On30 Model Railroad Waterline Hull Unpainted Cast Resin Kit FR65
16 LOG BRONC O On30 Model Railroad Waterline Hull Unpainted Cast Resin Kit FR65
$29.95
Time Remaining: 1d 22h 11m
Buy It Now for only: $29.95
86 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Craftsman Kit HL109S
86 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Craftsman Kit HL109S
$174.95
Time Remaining: 11d 54m
Buy It Now for only: $174.95
O On30 24 WATERLINE LOGS Model Railroad Scenery Unpainted Resin Details FR1665
O On30 24 WATERLINE LOGS Model Railroad Scenery Unpainted Resin Details FR1665
$26.95
Time Remaining: 22d 1h 24m
Buy It Now for only: $26.95
170 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Unpainted Kit HL110S
170 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Unpainted Kit HL110S
$289.95
Time Remaining: 22d 20h 5m
Buy It Now for only: $289.95

Other On30 Scale train items recently purchased through this site:

16 LOG BRONC O On30 Model Railroad Waterline Hull Unpainted Cast Resin Kit FR65
86 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Craftsman Kit HL109S
170 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Unpainted Kit HL110S
O On30 24 WATERLINE LOGS Model Railroad Scenery Unpainted Resin Details FR1665
Roy C Link Industrial Narrow Gauge Handbook 7mm O 14 model railways RARE