Really depends on how much they can earn for you, including x's.
£65-70 for a boy
can't drive, got tell him what do do every 5 mins, wake him up when its time to get out of the van, about as quick as a snail with a wooden leg, but can clean windows (very short working lifespan)
£120 - 150 totally independant, does what you require of him, no complaints, give him the address and spec and he will be able to do it, minimum sickness etc (goldust, make sure you look after him)