within reason its what you think is orth it, site rates cant be compared to doing a garage for someone. a bricky will want to earn £200-300 a day if working hard on a price at a private job so. maybe worth asking how long it will take and a price gainst the time? they's want a hodd carrier/labourer probally to mix up and load so that on top i gues but i cant see it being a huge amount