Hi colin
I do a lot of carpet and window cleaning work for a company, this is also spread out over a 100 mile radius, likewise they want a simple pricing struture so they know what to quote
What I do is to break the price down into 2 different packages, depending on when they want them cleaned.
Package 1, is if they give a set cleaning cycle of monthly, bi monthly 3 monthly etc as long as its not set for the same date and i can move the clean around to suit me in that month, then I give them a price to reflect the job, ie on the carpet clean side a set price for each floor I will clean or on windows x amount of windows by £xx
package 2 is if they want a set day or a one off, then the above is quoted plus a milage charge of 45p round trip plus a minimum charge of £30