Since this is a restaurant, and will likely be more regular (at least once per month) use “route” pricing. Do a window count, $0.50 per pane per side for the small square ones, and $1 per pane per side for the regular sized windows.
I personally hate doing interior windows, especially in restaurants, so you might consider doing a 1.5 multiplier for the interior total. Helps with dealing with the blinds, booths and clean up.
Now add 15% on top of that for insurance and workers comp costs etc. (even if you don’t have it now, you will need it one day, so build that into your price)
Take a look at the totals, and ask yourself: “Would I be happy to do this job for that price? How long do I think it will take me? Does it fit in with my hourly price goals? Is it close to other jobs that I have?”
Also, why did they call you for a quote? Did you approach them? Are their windows dirty and neglected? Did they lose their regular window cleaner? Or are they just shopping for a lower price?
Understanding the motivation of a potential client can go a long way to avoiding trouble. That being said, if you are just building your business you may not care what their motivation is and that is just fine.