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'.

VINTAGE QUALITY CRAFT MODELS HAYDENTON COVERED DEPOT KIT 103 HO SCALE
VINTAGE QUALITY CRAFT MODELS HAYDENTON COVERED DEPOT KIT 103 HO SCALE
$33.95
Time Remaining: 3h 3m
Buy It Now for only: $44.50
Rocky Mountain Railroads VolII DRGW Durango To Alamosa And Salida
Rocky Mountain Railroads VolII DRGW Durango To Alamosa And Salida
$40.00 (1 Bid)
Time Remaining: 12h 10m
A Century + Ten Of DRGW Narrow Gauge Freight Cars 1871 To 1981 2nd Edition
A Century + Ten Of DRGW Narrow Gauge Freight Cars 1871 To 1981 2nd Edition
$40.00
Time Remaining: 12h 16m
ULRICH COLLECTION O SCALE 1 48 On3 MODEL T FORD OIL TANKER ALL METAL
ULRICH COLLECTION O SCALE 1 48 On3 MODEL T FORD OIL TANKER ALL METAL
$49.99
Time Remaining: 15h 17m
Buy It Now for only: $49.99
O scale or On30 Logging Steam Donkey custom weathered after historic picture
O scale or On30 Logging Steam Donkey custom weathered after historic picture
$145.00
Time Remaining: 19h 31m
Logging Truck after historic pictures custom weathered lot 5 On30 O scale
Logging Truck after historic pictures custom weathered lot 5 On30 O scale
$115.00
Time Remaining: 19h 31m
Lot of Atlas Code 100 Switches
Lot of Atlas Code 100 Switches
$30.00
Time Remaining: 19h 47m
Historic Logging Truck custom weathered O or On30 scale lot 6
Historic Logging Truck custom weathered O or On30 scale lot 6
$89.00
Time Remaining: 20h 10m
Buy It Now for only: $89.00
On30 Steam Donkey Logging Wench Diorama custom weathered lot 14
On30 Steam Donkey Logging Wench Diorama custom weathered lot 14
$148.00
Time Remaining: 22h 53m
Logging Truck custom weathered lot 5 O scale or On30 scale
Logging Truck custom weathered lot 5 O scale or On30 scale
$145.00
Time Remaining: 22h 53m
Historic Bulldozer Logging Diorama custom weathered lot 11 O or On30 scale
Historic Bulldozer Logging Diorama custom weathered lot 11 O or On30 scale
$126.00
Time Remaining: 22h 53m
On30 Logging Steam Donkey Wench Diorama custom weathered handcrafted lot 4
On30 Logging Steam Donkey Wench Diorama custom weathered handcrafted lot 4
$128.00
Time Remaining: 22h 53m
Bulldozer Logging Diorama custom weathered hand crafted lot 4 O scale
Bulldozer Logging Diorama custom weathered hand crafted lot 4 O scale
$128.00
Time Remaining: 22h 53m
Spectrum No 27391 O On30 Logging And Mining Cars Skeleten Log Car Resin Logs
Spectrum No 27391 O On30 Logging And Mining Cars Skeleten Log Car Resin Logs
$45.00 (1 Bid)
Time Remaining: 23h 22m
Peco SL E596 HOn30 Left Hand Medium Radius Code 100 Turnout w Electrofrog
Peco SL E596 HOn30 Left Hand Medium Radius Code 100 Turnout w Electrofrog
$29.49
Time Remaining: 1d 4h 30m
Buy It Now for only: $29.49
Bachmann 29203 On30 Painted  Unlettered Whitcomb 50 Ton Center Cab w DCC
Bachmann 29203 On30 Painted Unlettered Whitcomb 50 Ton Center Cab w DCC
$243.99
Time Remaining: 1d 7h 20m
Buy It Now for only: $243.99
Micro Engineering 14 404 On30 Code 83 RH TURNOUT ESTATE SALE
Micro Engineering 14 404 On30 Code 83 RH TURNOUT ESTATE SALE
$26.00
Time Remaining: 1d 10h 43m
Buy It Now for only: $26.00
Rio Grande Narrow Gauge In Color Vol1 1947 1959
Rio Grande Narrow Gauge In Color Vol1 1947 1959
$40.00
Time Remaining: 1d 12h 22m
AY76 05 10 x Utz Fama Roco AlpinLine Gauge 0 m 145 DC 90 5107 Track MINT
AY76 05 10 x Utz Fama Roco AlpinLine Gauge 0 m 145 DC 90 5107 Track MINT
$36.97
Time Remaining: 1d 13h 31m
Buy It Now for only: $36.97
O On3 On30 1 48 SCALE WISEMAN MODEL SERVICES JI CASE STEAM TRACTION ENGINE KIT
O On3 On30 1 48 SCALE WISEMAN MODEL SERVICES JI CASE STEAM TRACTION ENGINE KIT
$149.95
Time Remaining: 1d 15h 3m
Buy It Now for only: $149.95
Old Ford Logging Truck custom weathered lot 4  O SCALE  ON30
Old Ford Logging Truck custom weathered lot 4 O SCALE ON30
$118.00
Time Remaining: 1d 15h 54m
Buy It Now for only: $118.00

Other On30 Scale train items recently purchased through this site:

ON3 Precision Scale Code 83 Straight Flex 4 pk Track
Peco SL 500 0 16 5 NARROW GAUGE On30 36 Flex Track Sections 12 NEW IN BOX
O On30 On3 Steel Water Tank Scenery Detail kit
Bachmann On30 25249 Painted Unlettered Bumble Bee 2 6 0 Steam Locomotive
HOn3 CUSTOM BUILT 24 TRUS ROD WOOD BOXCAR KDs STEEL WHEELS PAINTEDc
NWSL ON30 BACHMANN SHAY REGEAR KIT 2801 6
HOn3 CUSTOM BUILT 24 TRUS ROD WOOD REEFER KDs STEEL WHEELS PAINTED
HOn3 CUSTOM BUILT 24 TRUS ROD WOOD STOCK CAR KDs STEEL WHEELS PAINTEDb
Bachmann Spectrum On30 Rail Bus and Trailer Mint
ON30 DRL BACHMANN NARROWED COMBINE
HOn3 CUSTOM BUILT 24 TRUS ROD WOOD BOXCAR KDs STEEL WHEELS PAINTEDb
HOn3 CUSTOM BUILT 24 TRUS ROD WOOD BOXCAR KDs STEEL WHEELS PAINTEDa
ON30 BACHMANN FORNEY psuedo wwf 2 DCC SOUND
ON30 BACHMANN FORNEY psuedo wwf 7 DCC SOUND
On30 Chief Hosa Smoke Shop Rail Truck Scratchbuilt Powered
NEW HAWTHORNE VILLAGE On30 BACHMANN CONFEDERATE CIVIL WAR FLAT CAR
OOn30On3
Spectrum No 27391 O On30 Logging And Mining Cars Skeleten Log Car Resin Logs
309 Utility Pillar Crane Kit O Scale O On3 On30 by Crow River NICE
Micro Engineering 14 403 On30 Code 83 LH TURNOUT ESTATE SALE
Rocky Mountain Railroads VolII DRGW Durango To Alamosa And Salida
Bachmann Spectrum 28697
Bachmann 25963 On30 2 8 0 Locomotive DCC Tsunami SOUND
Narrow Gauge and Short Line Gazette Magazine lot of 13 Model Railroad 1979 1981
On30 Spectrum Convert Coach Observation Olive