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

Busch HOF 12342 Railroad Track Right  NEW ORIGINAL PACKAGING
Busch HOF 12342 Railroad Track Right NEW ORIGINAL PACKAGING
$31.88
Time Remaining: 2h 54m
Buy It Now for only: $31.88
Model Railroad Software Tools All Scales Brand New Version 184
Model Railroad Software Tools All Scales Brand New Version 184
$27.95
Time Remaining: 3h 52m
Buy It Now for only: $27.95
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: 5d 5h 16m
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: 14d 10h 34m
Buy It Now for only: $174.95
Hawthorne Village Civil War Confederate Express Railroad Track Set
Hawthorne Village Civil War Confederate Express Railroad Track Set
$89.99
Time Remaining: 15d 22h 3m
Buy It Now for only: $89.99
Roco 32403 H0e electric Light railway soft right new original packaging
Roco 32403 H0e electric Light railway soft right new original packaging
$35.24
Time Remaining: 16d 2h 10m
Buy It Now for only: $35.24
Narrow Gauge and Short Line Gazette Magazine lot of 13 Model Railroad 1979 1981
Narrow Gauge and Short Line Gazette Magazine lot of 13 Model Railroad 1979 1981
$27.99
Time Remaining: 20d 21h 34m
Buy It Now for only: $27.99
Busch 12342 2 Railroad Track Right 2 5 8In R  6 7 8In 225 H0F NEW
Busch 12342 2 Railroad Track Right 2 5 8In R 6 7 8In 225 H0F NEW
$31.46
Time Remaining: 21d 10h 56m
Buy It Now for only: $31.46
Busch 12339 eimerkettenbagger  BUSCH FIELD RAILWAY Kit HO HOF NEW
Busch 12339 eimerkettenbagger BUSCH FIELD RAILWAY Kit HO HOF NEW
$57.80
Time Remaining: 22d 7h 26m
Buy It Now for only: $57.80
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: 25d 11h 7m
Buy It Now for only: $26.95
On30 Scale Ultimate Railroad Prototype Picture CD Collection Set 25000+ images
On30 Scale Ultimate Railroad Prototype Picture CD Collection Set 25000+ images
$99.99
Time Remaining: 25d 22h 46m
Buy It Now for only: $99.99
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: 26d 5h 49m
Buy It Now for only: $289.95
Roco H0E 32403 Vineyard Track Light Railway Soft Right 24 Electric NEW + Box
Roco H0E 32403 Vineyard Track Light Railway Soft Right 24 Electric NEW + Box
$36.27
Time Remaining: 27d 52m
Buy It Now for only: $36.27
Roco H0E 32401 Vineyard Track Light Railway Soft Left 24 Electric NEW + Box
Roco H0E 32401 Vineyard Track Light Railway Soft Left 24 Electric NEW + Box
$36.27
Time Remaining: 27d 52m
Buy It Now for only: $36.27

Other On30 Scale train items recently purchased through this site:

Narrow Gauge and Short Line Gazette Magazine lot of 13 Model Railroad 1979 1981
On30 Scale Ultimate Railroad Prototype Picture CD Collection Set 25000+ images
170 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Unpainted Kit HL110S
Hawthorne Village Civil War Confederate Express Railroad Track Set
16 LOG BRONC O On30 Model Railroad Waterline Hull Unpainted Cast Resin Kit FR65
Model Railroad Software Tools All Scales Brand New Version 184
86 HOWE TRUSS DECK BRIDGE S On30 Model Railroad Structure Craftsman Kit HL109S
O On30 24 WATERLINE LOGS Model Railroad Scenery Unpainted Resin Details FR1665
Roco H0E 32401 Vineyard Track Light Railway Soft Left 24 Electric NEW + Box
Roco H0E 32403 Vineyard Track Light Railway Soft Right 24 Electric NEW + Box
Busch 12339 eimerkettenbagger BUSCH FIELD RAILWAY Kit HO HOF NEW
Busch 12342 2 Railroad Track Right 2 5 8In R 6 7 8In 225 H0F NEW
Roco 32403 H0e electric Light railway soft right new original packaging
Busch HOF 12342 Railroad Track Right NEW ORIGINAL PACKAGING