The All Clean Team,
I do just floor care such as what you've mentioned. I've only been in business a few months but I've researched the type of equipment you're talking about. I've gone to the Aztec website and have looked at all their equipment and have viewed all the videos on them, they look really nice! I went with similar equipment from Eagle Solutions, located in Adairsville, GA only because it was local to me.
The propane stripper machine is really powerful, in fact you WILL damage the floor if you leave it running while not moving. It is a whole lot nicer having to not deal with cords while working with propane or battery powered equipment.
Your prices seem right on for smaller facilities and offices, but like you said, you'll have to charge a lot less per square foot for larger buildings. I read on here to charge around 6 cents for janitorial services for skyscraper buildings, I'm not sure how that would translate into cleaning grocery stores but the price may or may not be in that neighborhood. As far as maintenance (auto-scrubbing & buffing) goes I know that for several Walgreens in my area a company charges by the service which isn't that much only $135 per visit although it is only 6000 square feet.
I would recommend calling a company that does those grocery stores and ask them what they charge, I did that with a local company and found out I charged 5 cents more per square foot but I didn't lower my price just because I found that out, besides that company is known for horrible quality (they got what they paid for.)
Anyway I hope some of this info helps, there's money to be made out there!