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

Bachmann On30 Scale Train Caboose Painted w round Roof  Lighted interior
Bachmann On30 Scale Train Caboose Painted w round Roof Lighted interior
$59.00
Time Remaining: 23d 5h 40m
Buy It Now for only: $59.00
HOn3 Silver Princess brass DRGW caboose in original box
HOn3 Silver Princess brass DRGW caboose in original box
$85.00
Time Remaining: 27d 18h 24m
Buy It Now for only: $85.00
Bachmann On30 Scale Train Caboose Off Set Cupola Caboose White Pass Yukon 26564
Bachmann On30 Scale Train Caboose Off Set Cupola Caboose White Pass Yukon 26564
$54.19
Time Remaining: 32d 12h 15m
Buy It Now for only: $54.19
Bachmann On30 Scale Train Caboose Off Set Cupola Durango  Silverton 26565
Bachmann On30 Scale Train Caboose Off Set Cupola Durango Silverton 26565
$54.19
Time Remaining: 32d 12h 15m
Buy It Now for only: $54.19

Other On30 Scale train items recently purchased through this site:

Bachmann On30 Scale Train Caboose Painted w round Roof Lighted interior
HOn3 Silver Princess brass DRGW caboose in original box
Bachmann On30 Scale Train Caboose Off Set Cupola Caboose White Pass Yukon 26564
Bachmann On30 Scale Train Caboose Off Set Cupola Durango Silverton 26565