Style perhaps, they certainly have caught the imagination and the bidders eye.
There is nothing in the engineering to justify the price (and I do have one), not so long ago they were almost difficult to sell. 10-11 years ago at a radio show (at the NEC, UK) I sold 3, with the metal plinths and soft covers for £100 the lot, but as they had cost in total less than £10 it was a good profit and that was the name of the game.
Only last year I bought a nice example on ebay (admittedly without the tin plinth) for £6o inc carriage, which seemed about right to me, since then prices have rocketed. But it appears now that it is only the metal plinth versions that command the very high prices.
If the metal plinth is not important to you, they were used in some 50's record players and radiograms, these can be a good source for a chassis.
I'm pleased with mine, it was a project and it's good to look at and nice to own, but it does not get much use, I have a number of other decks which sound so much better and are safer for my precious records.