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 locomotives'.

On30 WISEMAN MODEL SERVICES 1890s GILPIN STYLE BACHMANN SHAY CONVERSION KIT
On30 WISEMAN MODEL SERVICES 1890s GILPIN STYLE BACHMANN SHAY CONVERSION KIT
$119.95
Time Remaining: 11d 2h 33m
Buy It Now for only: $119.95
On3 On30 WISEMAN MODEL SERVICES NCNG SHORTY WHALEBACK TENDER KIT
On3 On30 WISEMAN MODEL SERVICES NCNG SHORTY WHALEBACK TENDER KIT
$49.95
Time Remaining: 13d 2h 44m
Buy It Now for only: $49.95
O SCALE On3 On30 WISEMAN MODEL SERVICES WESTMINSTER KEROSENE LOCOMOTIVE KIT
O SCALE On3 On30 WISEMAN MODEL SERVICES WESTMINSTER KEROSENE LOCOMOTIVE KIT
$37.95
Time Remaining: 19d 8h 32m
Buy It Now for only: $37.95

Other On30 Scale train items recently purchased through this site:

O SCALE On3 On30 WISEMAN MODEL SERVICES WESTMINSTER KEROSENE LOCOMOTIVE KIT
On30 WISEMAN MODEL SERVICES 1890s GILPIN STYLE BACHMANN SHAY CONVERSION KIT
On3 On30 WISEMAN MODEL SERVICES NCNG SHORTY WHALEBACK TENDER KIT