The most common complaint we hear from property managers switching vendors isn't that the old company was too expensive. It's that nobody could say exactly what the old company was supposed to be doing. 'General cleaning three nights a week' isn't a scope. It's a guess, and every missed task turns into an argument about whether it was ever included.
A real scope lists every area of the building and every task in it, with a frequency for each: trash nightly, restrooms nightly, vacuum traffic lanes nightly, full vacuum weekly, dust ledges and sills weekly, machine-scrub hard floors monthly, strip and wax twice a year. When it's written that way, both sides know what 'done' means and the price is tied to something concrete.
Ask any vendor you're considering four questions. Will the same crew be assigned to my building? Who inspects the work, and how often? Who do I call when something is missed, and how fast is it fixed? And can I see a certificate of insurance? A vendor who answers all four clearly is usually organized on the job too.
Finally, insist on a walkthrough before the quote. Any company that prices a building from square footage alone hasn't seen your restrooms, your floors, or your loading dock. The walkthrough is where the scope gets built, and it's free with any vendor worth hiring.