That's the way it is Tom. You can always tell people that you can be beaten on price, but not on quality of service. It takes us longer to clean insides. Any human being with an IQ over 43 will understand this, so we charge what we can get away with. I'm the same as most people who earn from their skill and witts. I charge what I can get away with and sustain.
Frrebies are for when you have a lot of time, and not enough work. If Mrs Jones wants insides, and I have Mrs Smith waiting for me to clean her outsides as arranged, why should she have to wait while I work for free at Mrs Jones's?? Doesn't make sebse. Whatever doesn't make sense, is usually not good business practice. If I find I have time for messing about for free, I'll go and get more customers.