3000 m2 between 2 gangs is 1500mts. if a gang does 100mts a day thats a 1000 mts a week . So the first week your gang may earn £ 2,375.0 gross and the second week but on the 3rd you are gonna run out of work mid week. chances you have some other job to fall back on are slim so that means you are gonna earn close to £1,200.00 quid between you all for the 3rd week.
Obviously there is skim to fall back. That may bump it up but could also disrupt you if they want some stupid areas done before you can hardwall.
But for the hardwall its gonna be about 600 a week after tax and labourer but before petrol if you average it out . And thats with no disruptions, everything ready, and not including beading out as soon as you get there.