Hope my response is not too late, and you've been ripped off yet by one of the local dry cleaners.
I had two pairs of lined John Lewis curtains dry cleaned by Hither Green Dry Cleaners after a recommendation by a friend. I couldn't find any local dry cleaners that would charge sensible prices.
I paid under 40 pounds for the above (free pick up and delivery for anything over 15 pounds I think) but this was by weight so can't say for yours. Still you couldn't find this kind of price around here. Excellent service and quality of cleaning.