Lol. No builder is going to price in a 70sq/m floor at £700 quid. A weeks work for a van, man and gang you'll be looking at around £2k, in Staffs. Possibly double in Gatwick.
I've not long finished my limecrete floor.
Took 2 days to dig out everything(£320 a day with digger)
1 day to get insulation to level(£260 a day)
4 days to lay(260 a day) Should be 3 but forced action mixer was delayed
I did 62SQ M with UFH/limestone flags/all costs included for about £9k.