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 trains'.

KATO N gauge 251 based super view Dancer appeared during coating 10 Car Set S
KATO N gauge 251 based super view Dancer appeared during coating 10 Car Set S
$275.67
Time Remaining: 1d 12h 21m
Buy It Now for only: $275.67
On30 Narrow Gauge Handmade Steam Boilers Rapairs Structure
On30 Narrow Gauge Handmade Steam Boilers Rapairs Structure
$119.99
Time Remaining: 4d 1h 30m
Kato N Gauge Kashima Waterfront Railway 6006 Girl  apos S  Pan Danzer Speci
Kato N Gauge Kashima Waterfront Railway 6006 Girl apos S Pan Danzer Speci
$56.04
Time Remaining: 19d 10h 18m
Buy It Now for only: $56.04
Kato N Gauge E231 System 0 Series Ch   S bu Line 4 Both hematopoiesis Set 1
Kato N Gauge E231 System 0 Series Ch S bu Line 4 Both hematopoiesis Set 1
$95.47
Time Remaining: 19d 10h 18m
Buy It Now for only: $95.47
Kato N Gauge E231 System 0 Series Ch   S bu Line 6 Both Basic Set 10 1520 M
Kato N Gauge E231 System 0 Series Ch S bu Line 6 Both Basic Set 10 1520 M
$173.80
Time Remaining: 19d 10h 18m
Buy It Now for only: $173.80
Kato HO Gauge HV 21 HO Uni Track Automatic Traffic Signal S Set 3 131 Japan
Kato HO Gauge HV 21 HO Uni Track Automatic Traffic Signal S Set 3 131 Japan
$139.80
Time Remaining: 19d 10h 18m
Buy It Now for only: $139.80
N Gauge 10 1147 181 System 100 Fee Collectors Stand The Time Azusa Six car
N Gauge 10 1147 181 System 100 Fee Collectors Stand The Time Azusa Six car
$177.53
Time Remaining: 19d 10h 18m
Buy It Now for only: $177.53
Kato N Gauge Diesel Train 58 Based Non air Conditioned car Express Iide 7 Car S
Kato N Gauge Diesel Train 58 Based Non air Conditioned car Express Iide 7 Car S
$250.45
Time Remaining: 19d 10h 18m
Buy It Now for only: $250.45
Rare railway model HO gauge KATSUMI Moha 484 Kuha 481 form rail F S
Rare railway model HO gauge KATSUMI Moha 484 Kuha 481 form rail F S
$600.00
Time Remaining: 23d 3h 4m
Buy It Now for only: $600.00

Other On30 Scale train items recently purchased through this site:

On30 Narrow Gauge Handmade Steam Boilers Rapairs Structure
KATO N gauge 251 based super view Dancer appeared during coating 10 Car Set S
Kato N Gauge Diesel Train 58 Based Non air Conditioned car Express I
Kato N Gauge Kashima Waterfront Railway 6006 Girl apos S Pan Danzer Speci
Kato N Gauge E231 System 0 Series Ch S bu Line 4 Both hematopoiesis Set 1
Kato HO Gauge HV 21 HO Uni Track Automatic Traffic Signal S Set 3 131 Japan
N Gauge 10 1147 181 System 100 Fee Collectors Stand The Time Azusa Six car
Kato N Gauge E231 System 0 Series Ch S bu Line 6 Both Basic Set 10 1520 M
Rare railway model HO gauge KATSUMI Moha 484 Kuha 481 form rail F S