Experience has taught me not to get involved with hagglers. If I don't join in with the haggling but get the job anyway, theyt are always on the look out for extra little freebies to "get their moneysworth. If I give in and start doing the job for their price, I get resentful after a while - and that feels uncomfortable. The only time I might consider it is possibly giving them £x off on maybe the 4th clean - as a one off, never to be repeated discount. That way, if they cancel after the 4th clean, at least I've made some reasonable money from it. However, by that time hopefully they have realised that I'm not some bob-a-job fly-by-night and the arrangement continues without hassle.