You can get a cost for the materials if you ask a supplier (such as Mike Wye who I used) - all you need to know is the floor area. However, for the rest, I did it myself with a couple of lads on day rates (one of who did the actual laying and levelling). I think you would be very lucky to find someone to quote for the labour at a sensible cost, but perhaps things have improved since I did mine in 2011.
Fortunately i am a plasterer with 30 years experience behind me. Just trying to see if it's worth getting on my knees again after 7 years of retirement.
Think i know the answer....!
Speak to Ty Mawr and Mike Wye directly with the floor area and you’ll get a materials price pretty simply. When I last did one, Mike Wye were far more responsive, didn’t make errors and were noticeably cheaper also, so that’s where I bought my materials. Just my experience from a single purchase, but you’ll get an answer pretty fast…