For inside and outside I think it would be worth $80 bi-weekly, $120 per month. But, depending on what your competition is, your workload and anything else, I would go as low at $40 bi-weekly, $60 per month. These prices are assuming you have tables in front of the windows and have to move the shelves with the black backs on them. It desn’t look bad at all, so I don’t think it would need an initial clean outside of just cleaning it like you usually would. I would skip the initial clean unless you have to break out the steel wool or scraper.
I usually price a given amount for weekly or bi-weekly or monthly then increase every step up by 50-percent. So, if I had a store for just weekly I may charge $20, but bi-weekly I increase it by 50-percent to $30 and monthly up 50-percent from that to 45-dollars then every month after that I typically charge an additional “surcharge” I guess you could say. So I may charge $10 per month extra and if they want it done every three months it would be $10 for each of the months past the first month plus the $45 for a total of $65.
Take anything you hear from me with a grain of salt. This is how I do it, but I’m a newbie too.