I charge 2x clean ,i live in notts so prob no use,when we canvass i will always put a quid on what price i give this way i cover myself,its always abit hard sometimes but if you set a min price you should be ok,i usually try and canvass for people who dont want council estates and min clean price around £9.00 ,
i guess its trial and error when finding a reliable canvasser
But we have as many problems with some window cleaners,getting payment etc,i work on a basis that i take payment for every £100 worth of work this way it covers me plus if the cleaner is not too happy with prices etc its only 10 customers and not the end of the world.