that is true, but u might want to take in consideration, tax credits and child care cost for which you got to work min of 16 hours and earn a min of 92 quid, to get of the gov, what u might find is that if you are only offering 15 hours a week, someone with a family might not want it as they are better of on the dole,
i was put on sick a few months ago for a month and my tax credit stoped with my child care, so had to come of the sick as was worse of just glad i was self employed so can change what i earn