I've only bought 1 bike on Ebay quite a few years ago and that was my Raleigh hybrid NOS still in the box. No issues. I've bought parts on Ebay as well without issue. I've bought and sold bikes on CL both complete and frames I stripped the parts on for other builds. No issues there either. CL or FB is where I will generally go if I'm looking for a rider or parts donor as I want to have a good look at it and maybe ride it as well as see any issues I can bring into price negotiation. I've also bought from thrift stores and garage sales.