Interesting about liners - to be honest, I don't want to buy something I'd have to dispose of after a single use, unless it was literally as cheap as greaseproof paper, which I don't think is true of the parchment. On mse, quite a few people use the bags that cornflakes come in as a tray liner, and I like that idea of repurposing something I already have
I wouldn't mind buying a sheet of silicon that could be re-used - have to skewer holes in it, though, to help air circulation.
The dehydrator I've bought is the £30 Westfalia one, Laser 2000 I think: round. Baby version, not the super duper square one

which I love the look of, but wasn't convinced it was the right buy for me.
Thanks for the input! Its all a complete mystery to me, so I'm glad of any conversation about it.