If you would have taken a second to look at the specs and search for actually comparable products you would find that there are, at least to my knowledge, no displays with the same resolution and higher refresh rates. This makes sense because 5k@60Hz already has incredibly high bandwidth requirements.
The best actually comparable product is an LG UltraFine 5K which comes in at 1,499€ msrp which is 246€ cheaper than Apple's Studio Display at 1,745€ msrp. Oh, and to no ones surprise, it also has a 60 Hz refresh rate.
So to answer your initial question: Yes, people do spend that kind of money on displays with "only" 60Hz.