Im always looking for M body stuff and specifically 77-80 truck parts (or whatever fits).

From a buyers point of view the way I see ebay is that it used to be great but then it got flooded with all the junk. You do a search for something and page after page of LED bulbs or chinese brake parts or whatever else is common. Then they messed up their search so you had to be more and more creative to not include that stuff.
In the mean time sellers were getting screwed with less sales and higher fees so they were raising their prices and shipping prices pretty much tripled or more in the last 20 years too,

Now when I can find parts either sellers want too much or by the time you add in shipping it's not worth it. And to make things worse we're not talking high dollar muscle cars here either so it makes it all the more harder to find parts or justify the cost.