we have used [industrial simple green]to clean awnings,
but first tried a small area where it over laps under the awning, this workrd for us.as far as price it was part of the bid on awhole building so cant help you there. but if you look up ac delcos Bulletin Board they have a price sheet you can somtimes go-bye.
hope this helps.
JIM & SHIRLEY
[TYPED BY JIM]
------------------