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 railroad'.

BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 603
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 603
$64.16
Time Remaining: 1h 25m
Buy It Now for only: $64.16
Busch 33573 Tt Gauge Lime Bucket Wagon  Zeitz   New Original Packaging
Busch 33573 Tt Gauge Lime Bucket Wagon Zeitz New Original Packaging
$43.84
Time Remaining: 19h 54m
Buy It Now for only: $43.84
NEVADA CENTRAL Sagebrush Narrow Gauge NEW BOOK
NEVADA CENTRAL Sagebrush Narrow Gauge NEW BOOK
$43.96
Time Remaining: 1d 10h 51m
Buy It Now for only: $43.96
HO Scale HOn3 SS Limited Dinky Creek Bridge Narrow gauge Railroad California
HO Scale HOn3 SS Limited Dinky Creek Bridge Narrow gauge Railroad California
$79.00
Time Remaining: 2d 11h 54m
GR 500 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Enclosed Side Coach
GR 500 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Enclosed Side Coach
$31.46
Time Remaining: 3d 2h 32m
Buy It Now for only: $31.46
GR 520 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Open Side Coach
GR 520 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Open Side Coach
$31.46
Time Remaining: 3d 2h 32m
Buy It Now for only: $31.46
GR 530 Peco OO9 Gauge Glyn Valley Freelance 4 Wheel Brake Coach Without Buffers
GR 530 Peco OO9 Gauge Glyn Valley Freelance 4 Wheel Brake Coach Without Buffers
$31.46
Time Remaining: 3d 2h 32m
Buy It Now for only: $31.46
Bachmann HOn30 Scale Narrow Gauge Train Open Wagon 77201 Thomas
Bachmann HOn30 Scale Narrow Gauge Train Open Wagon 77201 Thomas
$48.17
Time Remaining: 5d 6h 4m
Buy It Now for only: $48.17
Bachmann HOn30 Scale Narrow Gauge Train Box Van Red 77203 Thomas
Bachmann HOn30 Scale Narrow Gauge Train Box Van Red 77203 Thomas
$48.17
Time Remaining: 5d 6h 4m
Buy It Now for only: $48.17
SCRATCH BUILT WOODEN ON30 GAUGE O SCALE COVERED BRIDGE NARROW GAUGE LAYOUT 58
SCRATCH BUILT WOODEN ON30 GAUGE O SCALE COVERED BRIDGE NARROW GAUGE LAYOUT 58
$55.00
Time Remaining: 6d 9h 29m
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 315 nd
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 315 nd
$64.16
Time Remaining: 8d 21h 25m
Buy It Now for only: $64.16
Busch 31174 Tt Gauge Flat Wagon Samm 4818 New Original Packaging
Busch 31174 Tt Gauge Flat Wagon Samm 4818 New Original Packaging
$48.33
Time Remaining: 11d 4h 29m
Buy It Now for only: $48.33
Busch 31320 Tt Gauge Coal Wagons Fal  New Original Packaging
Busch 31320 Tt Gauge Coal Wagons Fal New Original Packaging
$35.15
Time Remaining: 11d 22h 14m
Buy It Now for only: $35.15
Busch 31321 Tt Gauge Coal Wagons Fal  New Original Packaging
Busch 31321 Tt Gauge Coal Wagons Fal New Original Packaging
$35.15
Time Remaining: 11d 22h 15m
Buy It Now for only: $35.15
Roco 32401 Narrow Gauge H0e Electric Light Railway Soft Left New Boxed
Roco 32401 Narrow Gauge H0e Electric Light Railway Soft Left New Boxed
$33.05
Time Remaining: 11d 22h 24m
Buy It Now for only: $33.05
Noch 58671 Hom Hoe Rhne Viaduct for Narrow Gauge Railway  Nip
Noch 58671 Hom Hoe Rhne Viaduct for Narrow Gauge Railway Nip
$39.41
Time Remaining: 12d 15m
Buy It Now for only: $39.41
Noch 58668 Hom Hoe Bruchstein Viadukt for Narrow Gauge Railway  Nip
Noch 58668 Hom Hoe Bruchstein Viadukt for Narrow Gauge Railway Nip
$52.55
Time Remaining: 12d 15m
Buy It Now for only: $52.55
Shinohara Code 70 Standard Gauge Turnout 6 Left Hand
Shinohara Code 70 Standard Gauge Turnout 6 Left Hand
$34.00
Time Remaining: 12d 6h 37m
Buy It Now for only: $34.00
BINKLEY KIT BUILT HOn3 NARROW GAUGE COLORADO NORTHERN CN ORE WAGON
BINKLEY KIT BUILT HOn3 NARROW GAUGE COLORADO NORTHERN CN ORE WAGON
$128.96
Time Remaining: 13d 12h 22m
Buy It Now for only: $128.96
Busch 31415 Tt Gauge Zweiseiten Kippwagen Fakks 6781  New in Original Package
Busch 31415 Tt Gauge Zweiseiten Kippwagen Fakks 6781 New in Original Package
$41.60
Time Remaining: 14d 15h 17m
Buy It Now for only: $41.60
Busch 31416 Tt Gauge Zweiseiten Kippwagen Fakks 6781  New in Original Package
Busch 31416 Tt Gauge Zweiseiten Kippwagen Fakks 6781 New in Original Package
$41.60
Time Remaining: 14d 15h 17m
Buy It Now for only: $41.60

Other On30 Scale train items recently purchased through this site:

Kemtron Brass HOn3 Narrow Gauge Passenger Chair Car Kit 401 DRGW Complete
Narrow Gauge Cumbres Toltec 6 CD PHOTO SET 1300 JPEGS
HO Scale HOn3 SS Limited Dinky Creek Bridge Narrow gauge Railroad California
SCRATCH BUILT WOODEN ON30 GAUGE O SCALE COVERED BRIDGE NARROW GAUGE LAYOUT 58
g Peco Streamline HO OO Gauge Narrow Gauge LH RH Turnout BOXED
Bachmann HOn30 Scale Narrow Gauge Train Open Wagon 77201 Thomas
NEVADA CENTRAL Sagebrush Narrow Gauge NEW BOOK
Bachmann HOn30 Scale Narrow Gauge Train Box Van Red 77203 Thomas
Kadee 813 ON3 HEIGHT GAUGE
Shinohara Code 70 Standard Gauge Turnout 6 Left Hand
Varian 0572 K7360 301 Ionization Gauge
Roco 32401 Narrow Gauge H0e Electric Light Railway Soft Left New Boxed
Busch 51553 Gauge H0 Ifa G5 59 Tank Truck 1550 Benzintankwagen Minol New
Busch 31323 Tt Gauge Coal Wagons Fals Zz New in Original Package
Busch 31322 Tt Gauge Coal Wagons Fals Zz New in Original Package
Busch 31416 Tt Gauge Zweiseiten Kippwagen Fakks 6781 New in Original Package
BINKLEY KIT BUILT HOn3 NARROW GAUGE COLORADO NORTHERN CN ORE WAGON
GR 530 Peco OO9 Gauge Glyn Valley Freelance 4 Wheel Brake Coach Without Buffers
GR 500 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Enclosed Side Coach
Busch 31320 Tt Gauge Coal Wagons Fal New Original Packaging
Busch 31321 Tt Gauge Coal Wagons Fal New Original Packaging
Electrofrog Medium Radius Right Hand Point Peco On30 O 165 gauge SL E595
GR 520 Peco OO9 Gauge Glyn Valley Tramway 4 Wheel Open Side Coach
Busch 33573 Tt Gauge Lime Bucket Wagon Zeitz New Original Packaging
Busch 31174 Tt Gauge Flat Wagon Samm 4818 New Original Packaging