I cant fault Window Cleaner Pro, dont regret buying it.
Try it out, you get a 45 day trial free
http://www.windowcleanerpro.com/?affurl=MS3AD62256742ACI tried Geroge but did not get on with it, i got on with WCP in an instant.
As for the windows, when i was trad i used to mop them up and had a small blade to do them, very tedious work, great with WFP but can be hard with trad.
As for pricing, price more than your average pain ie i charge around a £1 a window, so for similar size you might want to charge £1.50 - £2 (for the whole window, not the indiviual panes)