I don't know if their all legit, but there aot of Japanese component offerings at eBay that are priced crazy high.
As a consequence, they don't seem to sell very well and stay on eBay for very long periods.
Some components coming from Europe and here inthe US, are nkw priced quite a bit less than a decade ago, when the retrobike craze was happening all over the world. There are still some holdouts maintaining thrir high prices, but they are for harder to find components, so supply is dictating their prices.
I still remember it was quite fun in the 90's when sone of these now expensive stuff was still available for reasonable prices. Like I remember buying multiple NOS Mavic SSC derailleur sets for only a bit more than a hundred bucks each. Same goes for hard ti find brskesets like Spidel LSX sidepull brakesets (My favorite.), Which I bought multiple NOS sets of back then and NOS Stringlight A9 and Delta headsets. All of which helped me build up my component stash for my bike builds in the following years.....