First Large Building Bid - Help!

I was asked to bid a building wash at a hotel I do flat work for. I have done a few small homes and shops in the past but this one is big.

The building is 8 stories tall. I have figured it at 60,000sf of vertical walls. Constructed of brick, pre-cast concrete trim, and some dryvit with stucco.

i know I will need a lift. I have two 5.5gpm/3500psi machines with heat. I really think a soft wash set up may be the key though.

What's everyone's average sf cost on something like this? The work won't be completed until January so I have time to prepare and practice. I need to get a bid in soon though.