I’d be at $6/pane. Hard to see entryway but 19x6=114 x$6=$684 x2=$1368+entryway.
Maybe like $1499 for initial clean, in/out.
If they want it once a month, be prepared to also give them every other month and quarterly pricing, as well as just outside pricing.
Will they allow you in on a Saturday or Sunday? It will make your life a lot easier for insides.
Personally, I’d try to sell them on outsides only and entryway, after the initial clean. Do in/out once a year.
If using wfp, locate your water source.
Also, which side faces south? This will help you work around any direct sun. Sun will start east, wrap around south and end west.
Best wishes, hope you get it.