Just had a quote for 1100 quid, which is a bit over budget. Has anyone done this themselves and is it more trouble than it's worth, or could someone who's not totally inept manage it OK?

It's dead easy get on the roof if possible and feed the liner down get in phone contact with the person who pulls from the other end when they can reach.Wear very thick gloves as the liner is bloody sharp.If there are no major bends in the chimney it's quite easy I installed a small woodburner for under 500 quid by doing it myself

A neighbour of mine did it many years ago. IIRC, it involved little more than dropping a flexible foil tube down the chimney, then connecting it all up at the bottom. They had the hearth sealed up somehow. Prior to that, smoke had been coming into our house.

Dunno if £11 is steep or not really. I think you need to know what you're doing though.