Quoted from cottonm4:

There is a group of people whose hobby is depression glass. Google depression glass if you are curious. A friend I had a number of years ago dealt in depression glass. Just like pinball hobby vendors attend pinball shows, my friend and his wife owned the house next to the one they lived in and they used it as a warehouse for all of the depression glass that they would cart around to all of the glass shows. One day he finally admitted that they did not make any money hauling all of this glass around. It was their hobby and how they liked to meet people.
Most of the depression glass does not cost all that much per piece but when you are buying a complete set it can get pricy fairly fast.
Like anything produced, some items were more rare than others. My friend had a chance to score a particular yellow mayfair bowl. Only two were made and only one could be found and he got to buy it. He was ecstatic. He paid either $5,000.00 or $6000.00 and said it was worth $10K.
Here is where I come in. I have an Ebay account and I had sold enough items to have a nice range of positive feedback. I put his yellow bowl up for auction. My friend did not get his $10,000.00. He got his self buried in this piece of glass. But it did bring and honest bid of $4,000.00. I had several bidders all the way up. There was real interest to $4,000.00
Myself? I would not have given $2.00 for it unless I know I could have sold it for a lot of money. I am not into depression glass. But a lot of people are. My friend had made a lot more money in living life than I. Who was I to say he was an idiot for buying one piece of glass for that kind of money? He never asked to borrow money from me and he did not owe me anything so I would be out of line to tell him that he is crazy.
For the curious, here is a link to see Yellow Mayfair depression glass. Somewhere on one of my old G-4 Macs I still have a picture of that bowl, but finding it would be a challenge. Look at any piece of glass in this link and imagine it any one of them could have been that bowl for $4,000.00 Lot of money for a piece of glass. And consider that it went into a display cabinet and was probably never used at any time in it's life. And it is no different than a high dollar pinball machine that was not really designed to be played.
https://www.google.com/search?q=yellow+mayfair+depression+glass&tbm=isch&source=univ&sa=X&ved=2ahUKEwjOz7Sfl7nlAhUMKqwKHVNbDvwQsAR6BAgFEAE&biw=1280&bih=883