$1 per pane for outside only is my baseline, but that gets modified depending on how much I have to move and reach to clean.
Big floor to ceiling single panes? 3-4 bucks per is reasonable.
Only have two windows in your shop? Still costs 10 dollars.
On the other hand, if I’ve got 36 1’×3’ panes all clustered and stacked with minimal pole work, I’ll probably knock it down to 30 cause I know it will only take me 20 minutes at max.
Charge what you need to be happy with the job. For me, I don’t worry even about individual job prices as much anymore. If I can average North of 60 an hour for the day doing route work then I’m happy. Maybe some jobs pay better and some worse for the time and effort, but such is life.