I haven't got one but Channel 5's The Good Gadget Guide (new format of The Gadget Show) tested three recently - the Ninja, Salter and Daewoo. The £99 Daewoo won
You can watch that segment here
I've just looked on my local 'Nextdoor' group and there are three airfryers currently listed, all described as 'little used, as new' and two are offered free, the third is £30.
Might be worth your while checking out your local selling groups.