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

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: 6d 11h 27m
Buy It Now for only: $99.95
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: 25d 10h 5m
Buy It Now for only: $89.95

Other On30 Scale train items recently purchased through this site:

On3 On30 WISEMAN MODEL SERVICES COLORADO SOUTHERN PASSENGER COACH 70 KIT
On3 On30 WISEMAN SM 108 SHORTY COACH OPEN PLATFORM PASSENGER CAR KIT