'windows above 1st floor and above, frames and sills clean as standard plus genuine competitive prices'
should be changed to 1st floor windows and above. The repetition of above doesn't make sense.
Then a full stop before 'frames and sills clean as standard plus genuine competitive prices'. Plus it should be 'The frames and sills are cleaned as standard, plus genuine competitive prices.'
If you are going to impress me enough for me to take you on, I need to know you've bothered to check the letter reads well.
Dont mean to sound cold but I think its important. Some people wont notice, some people would throw it in the bin because of it.
I remember I ordered hundreds of canvassing flyers from the FWC and it was full of grammatical errors, and ended up having to make my own