I see a few of these undercutting threads, so here is my two cents.
Firstly I would never willingly or knowingly undercut another window cleaner. I don't think it does the industry any good.
I have seen people undercut one another until the work is simply unusable. The bigger nationwide customers are the worst. With the big nationals the turnover of window cleaners is huge, because everybody has a pop at them when they try to build their empire. The best way to win them is to punt a low price. Many of these jobs are now worthless, after years of undercutting in order to win the work.
If I am out canvassing and a punter asks me for a quote and say's "the lad that does it now does it for a tenner" my standard answer is that the best I can do is match it, and then put in my price. These people automatically go into the "Keep an eye on this one" file, if I decide to work for them at all. They will do the same thing with the next lad that comes along, so you can never really trust them.
Nine out of ten (or more) prices that I put in, go in blind. I simply don't know, and don't want to know what somebody else is doing it for. All I am interested in is whether or not it will be a reliable job for me.
If my price is lower than an existing windie then that is just tough, we live in a free trade market and we can charge what we like to who we like. We should be able to do this without fear of physical, verbal or psychological abuse from other people who have staked their claim on a particular area.
Imho the people who rant and rave about being undercut don't really know for sure that they have been undercut at all. They may be aware that the new guy is doing it for less, but it is unlikely he knew the origional price at all. So rather than deliberatly setting out to undercut an existing price, he would simply put in the one he is happy to work for. Thats competition.
rant over