So many people listing bikes on Facebook marketplace don't put the frame size on the advert and don't know how to measure that.  That's a key thing that I want to know.

Yard and garage sales. They are ready to get rid of them. Usually around  20 dollars.  If they wanted more, they would marketplace it.

Up North, search for Pushbike. Also search mis-spellings like Rally or Rayleigh.

I had a totally seized seat post that I eventually got out. I'd sprayed as much vinegar as I could get at it, and then stuck the seat post in a vice while two of us twisted the frame. It took enough force we were actually moving the bench that the vice was attached to, which also supported a drill press.

I'd also add Gumtree. It may be location sensitive but down here in Hampshire I have picked up dozens of good value 90's mountain bike. Some for free, most for under £50, including mint Marins, kool Konas and super Saracens. Personally I don't think I've ever seen a plastic crank but yes if I did then I would not even consider the bike, it would be basically rubbish. I generally look for any of the previously mentioned makes plus Specialized and Trek. That covers 90% of what comes up. Personally I would also not be so quick to dismiss a bike with a threaded steerer. You can get adapters if you wish but especially on road bikes the 1 inch alloy stems look fantastic, much better that most modern 11/8 stems that just look a bit clunky compared with a 3t polished alloy stem.
Otherwise well said on the rest.

If you put coke the soda into the bottom bracket and seal the seat post so it fills up the down tube in a day or two it will pop out as well

I hate dealing with a stuck seat post I have 2 frames I have to deal with that issue.... as for cheap bike I mostly hit my local swap meet but the real good deals come from the scrapers that drive around my neighborhood

Picked up a near mint MB-6 for $30. Keep looking. If they ask $100, you might arrive and find out a cable is bad, then tell them that will cost money to fix. Cut the price in half or more. I could not shift the front, went from $75 to $30. Avoid Shocks.

Love your passion for a retro bike.

WD40 in the seat tube through the bottom bracket and grab a pipe wrench. You may need to get a piece of wood to wedge the frame so you can really wrench on the post. If you're clever you can set it up where it won't damage anything other than the seat post.

scalex also works for the seattube
drill a pinhole if you really need to

Excellent tips, very helpful!

thank you very much for all the tips

USA has bike co ops and bike collectives they are community bike shops most every major cities have them

The difference between someone selling a frame and a complete bike is not that much. You have to do some work to get the parts off the complete bike, but after a few bike tear downs, you end up with enough for a decent bike build.

Big thumbs up to getting a bike with a threadless head set. Its almost impossible to find threaded forks that are the right length for a specific frame...too long, too short, not enough threading left...

Last time it was 5K, now 5.54K! Keep going, Craig!😉😉😉

I have a 1996 Kona NuNu with full Shimano STX set up. I would love to see this reconditioned. Is it something you’d be interested in buying??? Cheers, Rob

Definitely look at the crank.  If the crank has bolted chain rings its usually a higher quality bike.  If its a riveted crank/chainrings then it still may be a decent bike but its probably a mid to low level consumer bike and now it has to have some other redeeming quality like cool handlebars or nice paint.  I've bought bikes just so I could get the crank.

Style! Free or cheaper, less shipping cost vs selling price. How much of the parts I may want to replace. When in eBay always check feedback. 0 feedback = stole your money.

Use cola for stuck seat post a bike shop owner told me years ago and it worked for me. Give it a try it might help 👍 love your content