I've got a bit of insider info on this. A few years ago, I priced out "collector car" insurance with Hagerty for an R32 GT-R I was looking at buying. I was absolutely floored at how cheap a year was.
Purchase did not work out with the seller though -- he was a, uh... what's the nice term for this....... he was a fucking moron.
Sometimes the seller is the moron, sometimes it's us.
A couple of years ago I was talking to a guy in the NE (NH if i remember correctly) who wanted 35K for dark blue turbo 930. I stood firm at 32.5K, a price I thought was fair.
That car today is worth well over 100K.
Sometimes, I'm the moron.