Not necessarily. There are many good finds that come up on facebook marketplace and craigslist. True many of them are overpriced, but if you keep checking back on them, they will often drop drastically in price. People that may not particularly know what they have look on eBay, see a nice bike going for a certain price and they don't realize they won't get for their Peugeot or Raleigh what one will get for a Colnago, Pinarello or higher end Peugeot or Raleigh so they list them too high. Eventually they usually come down.

Be patient, familiarize yourself with what things signify a better quality bike and don't necessarily concern yourself with negative comments from some if they call something gas pipe or low end. Vintage bikes run a broad spectrum and this forum has them all. If you asked a question about a nice Raleigh Sport you have your eye on, some will put it down and others will simply regurgitate the same responses. But you will also get some helpful responses that will either tell you it is fairly priced for what it is or overpriced for what it is.

There are some knowledgable folks here and it amazes me that they can identify frames from details like braze ons, lugs or dropouts. I feel lucky if I can just identify something from a label on the down-tube or a head badge. But I know what I want to pay for something and if I think it is fair and it will scratch the itch I have, I'll buy it.