I was lucky because I got mine for about £188 from a german Ebay seller and then had a local person fit it for £100. I think my £288 is about as cheap as it gets. Could be around £600 for a supply and fit. I would shop around.
Many here have had them fitted and supply and fit is normally £5-600 there are places that also advertise original fiat mohair roof.....Fiat never made a mohair roof so talking sh*t and usually made in a local sewing factory. As are the ebay ones but much cheaper.
Mine was supplied and fitted (just before I bought the car), for £485 (mohair) by car hoods direct in Kent. The hood is just over 18 months old and apart from a few 'pulls' that a local cat has made in the fabric the hood and window are still like new.
I have met quite a few people who have used them on a number of different cars, everyone I know has had a good experience with them and has been happy with the end result.
Take a look for yourself and give them a call for a fitted price, supply only is £235 + VAT