Same thing with aquariums. If you want a 150 gallon you have to pay. If you want a 2000 gallon and are willing to go pick it up and move it, it's usually free.
I run into this with tools at auctions. Want a small milling machine you can move into your garage on your own? $2k. Want a giant one from the 60s that takes a crane to move in? $400
Exact thing happened to me when I first started collecting arcade games. I was ready to sell a Xenophobe cabinet, which is a massive, awkward monstrosity. Took a huge "loss" on it but at the time needed it out of my house and only cared that a potential seller could help get it up the stairs. :)
Ha, I knew someone who formerly worked for IGT. Said when he relocated he had a complete gambling machine (massively obsolete) in his living room. Including the 300 lbs something steel plate that is used to weigh it down. Put it on craigslist for free and said it was gone that evening, scrappers showed up and moved it out for him.
I've found church organs that were probably 100k+ for free before as well. You just need a giant place to put them...