These came from the closed Sheffield knife makers supply, I bought their building with remaining contents.
These appear to have been lost in their inventory. Pricing is based on a roughly 8 year old catalog.
It should be very obvious, each item is a single knife blade, not the full set.
The import paperwork shows these as coming from Mitsuboshi cutlery of Seki Japan, several of the KT series have manufacturer stickers stating they are made by Mitsuboshi cutlery, the packaging on the KT and MX series knife blades are identical as is the workmanship.
These are made from 6A stainless also called AUS-6, fairly similar to 440 stainless.
Please double check that the part number matches the photo of the item you want.