No way to pay 50 percent. i did this mistake and boy i was on a loss after paying for van, tax, ni etc etc.. Now I give my guy enough work to carry out each day to suit my targets. i pay just £6 per hour but i say its for a 10 hour day, basicaly i pay £60 pound a day and if it takes him 10 hours it would be £6 per hour but it pushes him to work hard and pull hes finger out and most days he does it in 5-6 hours which works out £10-£12 per hour. having the right priced compact round with the £10 min charge for a house you should be able to pull in a nice profit margine.
Mick