Just bought a toad
We found ours on craigslist. You need to be creative on your search criteria: Toad, Tow behind, Dinghy, tow car, etc. We found exactly what we were looking for. It will still cost us about 800-900 all in to get it complete (tow bar, MH wiring...) but that is better than the 4K some are quoting for a full installation. You might get lucky and find one with everything ready to play.
2006 Holiday Rambler Neptune 37' - New Source Engineering Trailing Arms and REK
2013 Chevy Sparc Toad
1970 Jeepster Commando (future toad???)