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

ON30 Bachmann Spectrum Jingle Bell Express Train Set 25012 North pole
ON30 Bachmann Spectrum Jingle Bell Express Train Set 25012 North pole
$279.99
Time Remaining: 45m
Buy It Now for only: $279.99
O On3 On30 1 48 SCALE WISEMAN MODEL SERVICES JI CASE STEAM TRACTION ENGINE KIT
O On3 On30 1 48 SCALE WISEMAN MODEL SERVICES JI CASE STEAM TRACTION ENGINE KIT
$149.95
Time Remaining: 47m
Buy It Now for only: $149.95
Bemo HOm HOe DR VT 133525 Wismarer Rail Bus TSL
Bemo HOm HOe DR VT 133525 Wismarer Rail Bus TSL
$299.99
Time Remaining: 47m
ON30 Spectrum Billboard Reefer John Harvards 27467 Freight Car
ON30 Spectrum Billboard Reefer John Harvards 27467 Freight Car
$54.99
Time Remaining: 1h 4m
Buy It Now for only: $54.99
ON30 ANNUALS MODEL RAILROADS
ON30 ANNUALS MODEL RAILROADS
$250.00
Time Remaining: 1h 9m
HAWTHORNE VILLAGE MAGIC OF DISNEY GOOFYS TOY SHOP
HAWTHORNE VILLAGE MAGIC OF DISNEY GOOFYS TOY SHOP
$29.99
Time Remaining: 1h 23m
 HAWTHORNE VILLAGE MAGIC OF DISNEY DONALDS GIFT WRAPPING
 HAWTHORNE VILLAGE MAGIC OF DISNEY DONALDS GIFT WRAPPING
$29.99
Time Remaining: 1h 27m
HAWTHORNE VILLAGE MAGIC OF DISNEY DISNEY EXPRESS TRAIN
HAWTHORNE VILLAGE MAGIC OF DISNEY DISNEY EXPRESS TRAIN
$29.99
Time Remaining: 1h 43m
HAWTHORNE VILLAGE MAGIC OF DISNEY STEAM LOCOMOTIVE  COAL TENDER
HAWTHORNE VILLAGE MAGIC OF DISNEY STEAM LOCOMOTIVE COAL TENDER
$29.99 (1 Bid)
Time Remaining: 2h 24m
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1920 1940
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1920 1940
$29.99
Time Remaining: 2h 37m
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1950 1970
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1950 1970
$29.99
Time Remaining: 2h 41m
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1980 1990
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1980 1990
$29.99
Time Remaining: 2h 50m
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1990 2000
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1990 2000
$29.99
Time Remaining: 2h 55m
ULRICH COLLECTION O SCALE 1 48 On3 MODEL T FORD BUS ALL METAL
ULRICH COLLECTION O SCALE 1 48 On3 MODEL T FORD BUS ALL METAL
$39.99
Time Remaining: 6h 39m
Buy It Now for only: $39.99
LAST ONE  RARE SIMPSON HOn3 Code 70 WYE STUB SWITCH
LAST ONE RARE SIMPSON HOn3 Code 70 WYE STUB SWITCH
$30.00
Time Remaining: 10h 7m
Buy It Now for only: $40.00
Sunset on the Rio Grande Southern 2 Volume Set
Sunset on the Rio Grande Southern 2 Volume Set
$125.00
Time Remaining: 11h
Roy C Link Industrial Narrow Gauge Handbook 7mm O 14 model railways RARE 
Roy C Link Industrial Narrow Gauge Handbook 7mm O 14 model railways RARE 
$73.07
Time Remaining: 16h 19m
HO Gauge Bachmann White Pass  Yukon Set
HO Gauge Bachmann White Pass Yukon Set
$289.99
Time Remaining: 23h 10m
Buy It Now for only: $289.99
Rails Neath the Palms 1st Edition 1983 by Robert Mann Hardback Gd Con Cover Iss
Rails Neath the Palms 1st Edition 1983 by Robert Mann Hardback Gd Con Cover Iss
$37.99
Time Remaining: 1d 2h 12m
Buy It Now for only: $37.99
O SCALE On3 On30 BANTA MODEL WORKS 6131 BO Hotel
O SCALE On3 On30 BANTA MODEL WORKS 6131 BO Hotel
$94.00
Time Remaining: 1d 2h 41m
Buy It Now for only: $94.00
HO Farm Wagons 2 pack 2501
HO Farm Wagons 2 pack 2501
$25.68
Time Remaining: 1d 3h 8m
Buy It Now for only: $25.68

Other On30 Scale train items recently purchased through this site:

LAST ONE RARE SIMPSON HOn3 Code 70 WYE STUB SWITCH
 HAWTHORNE VILLAGE MAGIC OF DISNEY DONALDS GIFT WRAPPING
Sunset on the Rio Grande Southern 2 Volume Set
HAWTHORNE VILLAGE MAGIC OF DISNEY GOOFYS TOY SHOP
HAWTHORNE VILLAGE MAGIC OF DISNEY STEAM LOCOMOTIVE COAL TENDER
27714 Bachmann On30 Caboose PRR w Lighted Interior
ON30 RAIL TRUCK CONVERSION KIT PASSENGER CAB FITS BACHMANN RAIL TRUCK
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1950 1970
HAWTHORNE VILLAGE MAGIC OF DISNEY PASSENGER CAR 1990 2000
On30 Bachmann Spectrum Rail Truck 29199 painted unlettered Kadees
BLACKSMITH SHOP WITH DETAILS HO HON30 HON3 KIT 4010 SEQUOIA MODELS
Bemo HOm HOe DR VT 133525 Wismarer Rail Bus TSL
HARTFORD PRODUCTS MUSEUM QUALITY 1203 SCALE KIT PARTS PLANS
Peco LK 555 Narrow Gauge Turntable Turn Table Nickel Silver 0 165 On30 Scale
On30 Bachmann Spectrum Gondola painted brown lettered for Robesonia Iron Co
PRECISION SCALE CO PK 608 HOn3 DRGW 30 REFRIGERATOR NIB
Lot of HOn3 Trucks
ON30 ANNUALS MODEL RAILROADS
Hawthorne village Civil War Confederate Express Locomotive Tender + 2 cars HO
bachmann on30 Rail Bus Trailer DCC
O On3 On30 WESTERN SCALE MODELS M 5 JAMISON CREEK HYDRO ELECTRIC POWER STATION
HOn3 DRGW ROTARY SNOW PLOW KIT BY DURANGO PRESS
HAWTHORNE VILLAGE MAGIC OF DISNEY DISNEY EXPRESS TRAIN
Bachmann Spectrum on302 4 4 Forney DCC Sound
BACHMANN HAWTHORNE VILLAGE CONFEDERATE CIVIL WAR TRAIN COLLECTION