Thats an impossible question to answer. It would depend on many factors. But if that was me in Leeds I would price £11.16 per hour for 25hrs.
So this would be £1209 pcm
costings as below.
Wage Rate £6.31
Monthly Payroll £683.58
Company NI £75.19
Holiday Pay £73.62
Equipment £6.50
Materials £34.18
Uniforms PPE £0.77
Insurance £6.24
Management Admin £68.36
Total monthly costs £948.44
Of course some of these costs are fictitious so in truth you should expect Materials to be around £20 and admin is nil, so the profit should be around £400 pcm.
But a lot will have to do with what they are paying now, trust me they will not pay much higher, if at all.
good luck
Drew