One reason to own something vintage and rare and expensive, if you need an excuse is that the right ones really appreciate in value.
I just saw the story of a rare Mercedes 300 SL roadster selling at auction for $1.045 million. It is the road version of the race car. the 300 SLR that Moss, etc dominated in back around 57. It particularly caught my eye as I came close to buying one about 1970, but was talked out of it. They were asking, if I recally in the high teens ,maybe $18,000. It was a whole car,ran and was drivable, but by no means show perfect. I dont know about any matching numbers, but I have never forgotten that car and wonder where it is today.
Does a rare car like that appreciate more than a rare airplane? Seems it may.