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

On3 On30 WISEMAN MODEL SERVICES COLORADO  SOUTHERN PASSENGER COACH 70 KIT
On3 On30 WISEMAN MODEL SERVICES COLORADO SOUTHERN PASSENGER COACH 70 KIT
$99.95
Time Remaining: 18h 53m
Buy It Now for only: $99.95
Peco SL E696 Streamline LH Left Hand Turnout Switch SM 32 Narrow Gauge Scale
Peco SL E696 Streamline LH Left Hand Turnout Switch SM 32 Narrow Gauge Scale
$54.99
Time Remaining: 17d 19h 30m
Buy It Now for only: $54.99
On3 On30 WISEMAN SM 108 SHORTY COACH OPEN PLATFORM PASSENGER CAR KIT
On3 On30 WISEMAN SM 108 SHORTY COACH OPEN PLATFORM PASSENGER CAR KIT
$89.95
Time Remaining: 19d 17h 31m
Buy It Now for only: $89.95
On3 On30 WISEMAN SM 101 DRGW OPEN PLATFORM BAGGAGE PASSENGER CAR KIT
On3 On30 WISEMAN SM 101 DRGW OPEN PLATFORM BAGGAGE PASSENGER CAR KIT
$89.95
Time Remaining: 19d 18h
Buy It Now for only: $89.95

Other On30 Scale train items recently purchased through this site:

On3 On30 WISEMAN SM 108 SHORTY COACH OPEN PLATFORM PASSENGER CAR KIT
On3 On30 WISEMAN SM 101 DRGW OPEN PLATFORM BAGGAGE PASSENGER CAR KIT
Peco SL E696 Streamline LH Left Hand Turnout Switch SM 32 Narrow Gauge Scale
On3 On30 WISEMAN MODEL SERVICES COLORADO SOUTHERN PASSENGER COACH 70 KIT