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

On3 On30 CRAFTSMAN SAN JUAN ENGINEERING DRGW 2 STALL ENGINE HOUSE KIT UNSTARTED
On3 On30 CRAFTSMAN SAN JUAN ENGINEERING DRGW 2 STALL ENGINE HOUSE KIT UNSTARTED
$149.95
Time Remaining: 4d 9h 21m
Buy It Now for only: $149.95
San Juan Car Co DRGW Drop Bottom Gondola Train Set 724 857
San Juan Car Co DRGW Drop Bottom Gondola Train Set 724 857
$600.00
Time Remaining: 7d 7h 6m
Buy It Now for only: $600.00
San Juan Car Co Gramps Tank Car Set 63 88131
San Juan Car Co Gramps Tank Car Set 63 88131
$600.00
Time Remaining: 7d 7h 13m
Buy It Now for only: $600.00
San Juan Car Co Gramps Tank Car Set 88153 88166
San Juan Car Co Gramps Tank Car Set 88153 88166
$500.00
Time Remaining: 7d 7h 25m
Buy It Now for only: $500.00

Other On30 Scale train items recently purchased through this site:

San Juan Car Co Gramps Tank Car Set 88153 88166
San Juan Car Co DRGW Drop Bottom Gondola Train Set 724 857
San Juan Car Co Gramps Tank Car Set 63 88131
On3 On30 CRAFTSMAN SAN JUAN ENGINEERING DRGW 2 STALL ENGINE HOUSE KIT UNSTARTED