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

BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 315 nd
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 315 nd
$67.70
Time Remaining: 2d 20h 27m
Buy It Now for only: $67.70
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 606
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 606
$67.70
Time Remaining: 4d 17h 10m
Buy It Now for only: $67.70
HAWTHORNE VILLAGE On30 BACHMANN CONFEDERATE CIVIL WAR J E B STUART
HAWTHORNE VILLAGE On30 BACHMANN CONFEDERATE CIVIL WAR J E B STUART
$59.99
Time Remaining: 9d 7h 56m
Buy It Now for only: $59.99
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 3145 n
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 3145 n
$67.70
Time Remaining: 10d 16h 41m
Buy It Now for only: $67.70
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 605
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 605
$67.70
Time Remaining: 13d 19h 21m
Buy It Now for only: $67.70
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
$49.99
Time Remaining: 17d 6h 7m
Buy It Now for only: $49.99
ON3 ON30 SILVER CITY MODELS DRGW 1872 12 4 WHEEL BOX CAR KIT
ON3 ON30 SILVER CITY MODELS DRGW 1872 12 4 WHEEL BOX CAR KIT
$36.00
Time Remaining: 20d 22h 10m
Buy It Now for only: $36.00
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
$49.99
Time Remaining: 23d 6h 19m
Buy It Now for only: $49.99
Stonewall Jackson Box Car Hawthorne Village Civil War Confederate Express NEW
Stonewall Jackson Box Car Hawthorne Village Civil War Confederate Express NEW
$49.99
Time Remaining: 23d 6h 20m
Buy It Now for only: $49.99
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 603
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 603
$67.70
Time Remaining: 25d 27m
Buy It Now for only: $67.70
On30 Fat Albert Boxcar Conversion to fit Bachmann 18ft flat car
On30 Fat Albert Boxcar Conversion to fit Bachmann 18ft flat car
$37.00
Time Remaining: 29d 1h 57m
Buy It Now for only: $37.00
Hawthorne Village Silver Moon Moonlight Express Wolf Walk Box CarCrossing NEW
Hawthorne Village Silver Moon Moonlight Express Wolf Walk Box CarCrossing NEW
$29.99
Time Remaining: 29d 6h 25m
Buy It Now for only: $29.99
Bachmann On30 Scale Train 18 Freight Cars Box Car 2 per box 26501
Bachmann On30 Scale Train 18 Freight Cars Box Car 2 per box 26501
$91.82
Time Remaining: 30d 5h 1m
Buy It Now for only: $91.82
Bachmann On30 Scale Train 18 Box Car W Murphy Roof Gray 2 box 26553
Bachmann On30 Scale Train 18 Box Car W Murphy Roof Gray 2 box 26553
$91.82
Time Remaining: 30d 5h 1m
Buy It Now for only: $91.82
Bachmann On30 Scale Train Box Car South Pacific Coast Sunset Logo 27002
Bachmann On30 Scale Train Box Car South Pacific Coast Sunset Logo 27002
$45.91
Time Remaining: 30d 5h 2m
Buy It Now for only: $45.91
Bachmann On30 Scale Train Box Car Mineral Red Data Only 27098
Bachmann On30 Scale Train Box Car Mineral Red Data Only 27098
$45.91
Time Remaining: 30d 5h 2m
Buy It Now for only: $45.91
Bachmann On30 Scale Train Box Car Oxide Red Data Only 27097
Bachmann On30 Scale Train Box Car Oxide Red Data Only 27097
$45.91
Time Remaining: 30d 5h 2m
Buy It Now for only: $45.91
Bachmann On30 Scale Train Box Car White Pass  Yukon 27001
Bachmann On30 Scale Train Box Car White Pass Yukon 27001
$45.91
Time Remaining: 30d 5h 2m
Buy It Now for only: $45.91
Bachmann HOn30 Scale Narrow GaugeTrain Box Van Blue 77202 Thomas
Bachmann HOn30 Scale Narrow GaugeTrain Box Van Blue 77202 Thomas
$48.17
Time Remaining: 30d 5h 6m
Buy It Now for only: $48.17

Other On30 Scale train items recently purchased through this site:

On30 Fat Albert Boxcar Conversion to fit Bachmann 18ft flat car
ON3 ON30 SILVER CITY MODELS DRGW 1872 12 4 WHEEL BOX CAR KIT
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
Stonewall Jackson Box Car Hawthorne Village Civil War Confederate Express NEW
Bachmann On30 Scale Train Box Car South Pacific Coast Sunset Logo 27002
Bachmann On30 Scale Train Box Car White Pass Yukon 27001
Bachmann On30 Scale Train Box Car Mineral Red Data Only 27098
A Plan For VIctory Box Car Hawthorne Village Civil War Confederate Express NEW
Hawthorne Village Silver Moon Moonlight Express Wolf Walk Box CarCrossing NEW
Bachmann On30 Scale Train 18 Box Car W Murphy Roof Gray 2 box 26553
Bachmann On30 Scale Train 18 Freight Cars Box Car 2 per box 26501
Bachmann On30 Scale Train Box Car Oxide Red Data Only 27097
HAWTHORNE VILLAGE On30 BACHMANN CONFEDERATE CIVIL WAR J E B STUART BOX CAR 005
Bachmann HOn30 Scale Narrow GaugeTrain Box Van Blue 77202 Thomas
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 3145 n
BINKLEY KIT BUILT HOn3 NARROW GAUGE DENVER RIO GRANDE DRGW BOX CAR WAGON 315 nd
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 606
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 603
BINKLEY KIT BUILT HOn3 NARROW GAUGE DSPPRR DENVER SOUTH PARK REEFER BOX CAR 605