I've bought and sold quite a bit of stuff on Marketplace (I'm using that term for both Marketplace and Facebook buy/sell groups).  Sold a couple semi tractors, a semi trailer, a couple grain bins (they went to Alabama) , a M&W ripper, bought a couple LP tanks,  bought a tractor, some small stuff, on and on  In fact Friday I bought an engine we are planning on putting on an irrigation pump.  Oh, and I have a 1/64 scale 4586 tractor and 1/16 scale IH plow in transit someplace I bought last week.  I've bought several toys on Facebook groups.

One of the biggest problems with online sales is things either sell immediately or sit around 6 months.  Doesn't matter if it's Marketplace, Craig's List, or AgTalk Classifieds.  I have found if you see something you might be interested in you better act immediately.

I mentioned there is Marketplace and there are Facebook buy/sell groups.  Sometimes things show up on both, sometimes not.  And the eBay search engine is generations ahead of Marketplace.   Do a little searching for groups in your area of interest besides just Marketplace.

Also it's getting kind of like Craig's List, you KNOW you're going to get called by a scammer.  And there's going to be tire kickers (I am often one.  I tend to ask questions and try to get an assurance they will hold it for me before I travel 2 hours).  And there will be no shows.  If you're going to be easily offended or lose patience it isn't the place for you.

Remember what I was taught in Xerox sales school 35 years ago.  80% of the people are easy to get along with, 18% are difficult, 2% are impossible.  Your job is find that 2% and stay away from them.