Need to bid on a multi tenant office building,how much to charge to clean 7 days per week?

it's a medical building with multi tenants,do i price it as a whole 30000 sq feet or by the hour 2 of us do it in 5-6 hours 7xweek. there is a walk-in clinic very busy high traffic, a lab, podiatrist, diabetes centre, several family doctors, 19 washrooms, 4 kitchens, and more, front lobby is tiles, linoleum floor, and a bit of carpet. the winter is brutal from high traffic and salt,lots of garbage nightly and cardboard. we are underpaid big time looking for suggestions so i can renegotiate. i was told by someone who does residential cleaning and she said she would price around 125000.00 per year i was thinking around 8000per month any help appreciated thanks