good luck if you can get those prices, i have just had a bartering session over a contract for a four storey block, basically it worked out at roughly just over £1.00 a window regardless of height and I wasn't the cheapest!! do you increase prices for different cleaning schedules, ie monthly, bi monthly quarterly etc?
I wouldn't have even got a call back if i went over £2.oo per window, be it second floor or fifth floor!!