Used to all the time. A 185/65/14 was $75 new during the last gas/economic crisis. Used in great shape from a junkyard was $5-10. This was back when we had that steel/ import tire tariff.
Three years to a year ago I could get four new tires from DTD for $100 and the price of used ones bumped up to $20-25. I would still get one used one for a project car or emergency if the date code was recent and the tread "perfect" if I didn't have time or foresight to buy on a DTD holiday sale.
Now it seems like everyone's a used tire dealer and they're all overpriced. Craigslist kind of wrecked the scene by separating used tires from general auto parts. I figure it's the economy doing better, so people are buying new cheap tires again. Walmart, Amazon, and eBay are new competitors for cheap new rubber.
The best tire deal, having a machine, is buying tires *or* rims I need then selling the part I don't need. There are people out there who'll buy another "gently used" set on rims then practically give away their existing rims with bald tires still attached. My prius snow rims cost me $60 but I had two good tires I got $30 out of, leaving me with the rims for $7.50 apiece plus $280/ton to get rid of two bald tires, probably a buck a tire.
I did have one blowout but couldn't have seen it coming. Tire held air, was never driven flat to ruin the scalloping inside, no plugs, o date, just went bang one hot summer day. This in 10+ years of driving.