Thanks for the suggestions everyone,
I did pop "air fryers" in the search box before posting but I didn't get any results - don't know what I did wrong
I'd like one with a reasonable capacity big enough to cover a one person chicken and veg traybake anyway.
I did look at the Ninja which like the Sage also dehydrates as I'd need to get rid of my dehydrator if I get one but is far less than £300 thankfully.
I think I will continue to ponder for a bit.