I bought my PQ1500s used from an individual on eBay- she put up a video showing her sewing on it. I got it for a great price and she had it well packed for shipping. It’s never given me any trouble. Great machine.
I bought my SweetSixteen used from an individual on eBay and drove three hours to pick it up. Got it for a great price, it was nearly new and she threw in lots of extras. Again, never had any problems with it.
I’ve also bought two vintage machines off eBay from individuals- machines were well packed. One had a problem so I contacted the seller about returning it. He refunded my money including shipping and told me to keep the machine.
My featherweight was in a junk shop window. It was covered in dirt and they didn’t think it worked, so were planning on turning it into a lamp.
I have no problem buying from individuals on eBay, but I stick with folks who have high ratings and I ask a lot of questions before bidding, so their answers are on eBay- that means that if the machine isn’t as described I am likely to get a refund.
You do need to be careful when buying used, especially if you can’t see and try out the machine in person, but there are some good deals out there.
Rob