Craigslist!
Think I've bought every vehicle, sled, camper, new tires, etc off Craigslist in the last 5 years.
If you're in the Twin Cities you have a huge search area that is within a 4 hr drive. From all of Northern WI and MN to Des Moines, Cedar rapids, Chicago, Madison, Milwaukee, etc.
I've found that way less people use the pay sites like RV trader, Auto Trader, Fleabay these days.
You do have to wade through some BS adds, but generally people selling expensive stuff are legit.
Picked up a SRT8 Charger for my wife last year, immaculate condition, owned by one of the richest people I've ever seen (like a $5M estate with a staff of servants) for about $5k less than any other ones seen.
Got the new camper for $12k, almost perfect condition. Again, way less $ than all other sources looked at.
New, 18 mi on it, Polaris 800 snowmobile last winter for $5k less than new.
I could go on............