I used eBay and craigslist for leads when shopping. I drove all over the northeast and NY state before finding a deal.
Many years ago, I bid (and won) an eBay auction from a seller in upstate NY. While making arrangements on the phone he asked me to hang on for a minute and started talking to someone in the background . . . they were discussing placing "shill" bids on an auction that was ending soon! After getting off the phone, I did a little more research . . . looks like he had several eBay accounts . . . he would list everything "no reserve" so you felt that you had a chance at a deal BUT he would put bids in to up the price to his minimum. MANY of his sales fell through and RV's were relisted, sometimes under another ID. Back then (when eBay didn't scramble/block I.D.'s)
you could see his different accounts bidding back and forth on each other's items.
Needless to say, I chose NOT to make the 6 hour drive with cash in hand. If he was sleazy enough to do that, what else would he hide to make a sale???
I think the key is to learn enough and look enough to be able to recognize a good deal AND then be ready to act on it. I'm still kicking myself because the first RV (private seller from craigslist)
that I looked at when I was buying a couple of years ago (when gas first jumped past $4/gal)
was worth about $20,000 and the seller would have taken $12,000. In the 2 days it took me to realize what a deal it was . . . it was gone!