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

Hon3 Blackstone Models DRGW High Side Gondola Road Number 9206  Weathered
Hon3 Blackstone Models DRGW High Side Gondola Road Number 9206 Weathered
$54.95
Time Remaining: 8h 1m
Black Stone DRGW High side Gondola  817 Factory Painted HOn3               
Black Stone DRGW High side Gondola  817 Factory Painted HOn3               
$51.50 (4 Bids)
Time Remaining: 1d 12m
Black Stone DRGW 826 Drop Bottom Gondola HOn3 Kadee Couplers Factory painted
Black Stone DRGW 826 Drop Bottom Gondola HOn3 Kadee Couplers Factory painted
$41.00 (2 Bids)
Time Remaining: 5d 1h 17m
TWO BACHMANN HIGHSIDE GONDOLASON THE SAME SET OF TWO 2 TRUCKS
TWO BACHMANN HIGHSIDE GONDOLASON THE SAME SET OF TWO 2 TRUCKS
$75.95
Time Remaining: 5d 3h 9m
Buy It Now for only: $98.75
ON3 ON30 SILVER CITY MODELS DRGW 1872 17 4 WHEEL GONDOLA CAR KIT
ON3 ON30 SILVER CITY MODELS DRGW 1872 17 4 WHEEL GONDOLA CAR KIT
$26.00
Time Remaining: 10d 2h 18m
Buy It Now for only: $26.00
WINTER FUN GONDOLA 2009 HAWTHORNE MM HOLIDAY EXPRESS FIGURE AND TRACK NIB
WINTER FUN GONDOLA 2009 HAWTHORNE MM HOLIDAY EXPRESS FIGURE AND TRACK NIB
$84.99
Time Remaining: 11d 3h 30m
Buy It Now for only: $84.99
Bachmann BAC27201 On30 Spectrum Gondola Undec Oxide Red Data Only
Bachmann BAC27201 On30 Spectrum Gondola Undec Oxide Red Data Only
$31.84
Time Remaining: 13d 3h 25m
Buy It Now for only: $31.84
Bachmann BAC27202 On30 Spectrum Gondola MOW Gray
Bachmann BAC27202 On30 Spectrum Gondola MOW Gray
$31.84
Time Remaining: 13d 3h 26m
Buy It Now for only: $31.84
Bachmann BAC27203 On30 Spectrum Gondola WPY
Bachmann BAC27203 On30 Spectrum Gondola WPY
$31.84
Time Remaining: 13d 3h 27m
Buy It Now for only: $31.84
Bachmann Hawthorne Village Coca Cola Gondola Car  Tracks Holiday Express Train
Bachmann Hawthorne Village Coca Cola Gondola Car Tracks Holiday Express Train
$29.99
Time Remaining: 18d 1h 14m
Buy It Now for only: $29.99
On3 On30 WISEMAN CSM004 BACKWOODS LOGGING MINING 4 WHEEL LOW SIDE GONDOLA KIT
On3 On30 WISEMAN CSM004 BACKWOODS LOGGING MINING 4 WHEEL LOW SIDE GONDOLA KIT
$27.95
Time Remaining: 20d 2h 54m
Buy It Now for only: $27.95
RIO GRANDE MODELS DRGW AIR DUMP GONDOLA
RIO GRANDE MODELS DRGW AIR DUMP GONDOLA
$25.00
Time Remaining: 24d 11h 53m
Buy It Now for only: $25.00

Other On30 Scale train items recently purchased through this site:

Black Stone DRGW 826 Drop Bottom Gondola HOn3 Kadee Couplers Factory painted
ON3 ON30 SILVER CITY MODELS DRGW 1872 17 4 WHEEL GONDOLA CAR KIT
Black Stone DRGW High side Gondola  817 Factory Painted HOn3               
On3 On30 WISEMAN CSM004 BACKWOODS LOGGING MINING 4 WHEEL LOW SIDE GONDOLA KIT
Bachmann Hawthorne Village Coca Cola Gondola Car Tracks Holiday Express Train
Hon3 Blackstone Models DRGW High Side Gondola Road Number 9206 Weathered
RIO GRANDE MODELS DRGW AIR DUMP GONDOLA
WINTER FUN GONDOLA 2009 HAWTHORNE MM HOLIDAY EXPRESS FIGURE AND TRACK NIB
Bachmann BAC27202 On30 Spectrum Gondola MOW Gray
Bachmann BAC27201 On30 Spectrum Gondola Undec Oxide Red Data Only
Bachmann BAC27203 On30 Spectrum Gondola WPY
TWO BACHMANN HIGHSIDE GONDOLASON THE SAME SET OF TWO 2 TRUCKS