Because there is no dealer network so you can only buy from Ketron themselves.
I bought a Midjpro from Ketron UK to try and use it as an arranger module because I liked the sounds and styles.
Shortly afterwards, the SD40 came out and I wanted to part exchange my Midjpro for an SD40.
Ketron said they don't do part exchanges and refused to take the Midjpro off me.
Since then, the SD90 has been introduced and I would willingly part exchange for an SD90 but, due to Ketron's method of trading, I am stuck with the Midjpro.
Hard to sell a Ketron privately although they are brilliant instruments.
The fact that internet sales are decimating keyboard dealers doesn't help. Only one music shop left in Sheffield.