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

Kato HO Gauge HO AC Adapter for 22 083 Railway Model Supplies
Kato HO Gauge HO AC Adapter for 22 083 Railway Model Supplies
$40.10
Time Remaining: 5d 18h 51m
Buy It Now for only: $40.10
Railway Post Office Baggage Car Tokaido Sanyo 6 Car Set Model Train by
Railway Post Office Baggage Car Tokaido Sanyo 6 Car Set Model Train by
$178.49
Time Remaining: 5d 18h 51m
Buy It Now for only: $178.49
Kato N Gauge E235 Series Yamanote Line Basic Set 4 Both 10 1468 Railway Model
Kato N Gauge E235 Series Yamanote Line Basic Set 4 Both 10 1468 Railway Model
$137.97
Time Remaining: 5d 18h 51m
Buy It Now for only: $137.97
Kato N Gauge Smart Controller AC Adapter not included 22 019 Railway Model Sup
Kato N Gauge Smart Controller AC Adapter not included 22 019 Railway Model Sup
$149.33
Time Remaining: 5d 18h 51m
Buy It Now for only: $149.33
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: 9d 11h 37m
Buy It Now for only: $600.00
KATO N gauge JR Shikoku 2000 series 3 car set 10 1504 Diesel car Railway model
KATO N gauge JR Shikoku 2000 series 3 car set 10 1504 Diesel car Railway model
$167.00
Time Remaining: 10d 3h 49m
Buy It Now for only: $167.00
Kato Japan 14 503 1 Chibi Den Streetcar Tram Train N scale Railway model
Kato Japan 14 503 1 Chibi Den Streetcar Tram Train N scale Railway model
$83.60
Time Remaining: 24d 18h 24m
Buy It Now for only: $83.60

Other On30 Scale train items recently purchased through this site:

Kato Japan 14 503 1 Chibi Den Streetcar Tram Train N scale Railway model
Rare railway model HO gauge KATSUMI Moha 484 Kuha 481 form rail F S
Kato N Gauge E235 Series Yamanote Line Basic Set 4 Both 10 1468 Railway Model
KATO N gauge JR Shikoku 2000 series 3 car set 10 1504 Diesel car Railway model
Kato HO Gauge HO AC Adapter for 22 083 Railway Model Supplies
Railway Post Office Baggage Car Tokaido Sanyo 6 Car Set Model Train by
Kato N Gauge Smart Controller AC Adapter not included 22 019 Railway Model Sup