Life must be filled up

The people at Dean Street Press are issuing more reprints of the Ludovic Travers series by Christopher Bush in May. Books 31 to 40 and they still won’t have finished! Here’s what they say:
‘May 4 2019 will soon be upon us, and what better time to release the next instalment of our Christopher Bush novels - sunny, funny and guaranteed to confound the keenest of mystery hounds…These novels…also feature lots of interesting aspects of the England of the time, now dealing with the immediate post-war period. These are all ably noted in the fascinating new introductions by Crime Fiction historian Curtis Evans.’
( the books )

I sometimes mention the enterprising Dean Street Press, who kindly send me the occasional ebook for review. I got another one yesterday because they’re bringing out the next batch of crime novels by Christopher Bush. I browsed their titles on Amazon and found Murder at Fenwold, which I quite enjoyed, listed at £1,049.00! I thought it must be a mistake and checked it again today. The same price and there are two copies on eBay, even more expensive. Why? And is this another tulip mania of the book world, where people will buy and get their fingers burnt?