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

BTS S SN3 McCabe Lumber Co Complete Set Of 7 Camp Cars New
BTS S SN3 McCabe Lumber Co Complete Set Of 7 Camp Cars New
$400.00
Time Remaining: 8d 1h 56m
Buy It Now for only: $400.00
New  Spectrum Narrow Gage On30 Camp Car Bunk Car 26998
New Spectrum Narrow Gage On30 Camp Car Bunk Car 26998
$69.95
Time Remaining: 23d 21h 57m
Buy It Now for only: $69.95

Other On30 Scale train items recently purchased through this site:

New Spectrum Narrow Gage On30 Camp Car Bunk Car 26998
BTS S SN3 McCabe Lumber Co Complete Set Of 7 Camp Cars New