Off market office valuation and buyer broker compensation
Hi, I am purchasing a business and the office building is up for sale as well (Seattle area).  The business is downstairs and there is a small \~700sqft office on the second level that is empty. The seller of the building has a broker that is representing him. I am wanting to do my own due diligence and am looking to hire my own broker. I was told by a few brokers to ask about the commission compensation (they said usually 50/50) and the selling broker said it is not split, he has an override. He will retain 4% and my broker will get 1%.  
The selling broker is saying he is doing all the work, that my broker just needs to come up with the valuation and other small paperwork. What would be a fair compensation/commission split? Are there ways to have someone come up with a valuation without hiring my own broker or is that a bad idea?  


Also, it seems in the current climate that commercial real estate is not appreciating nearly as much/fast as residential. Is it a good idea to spend all this capital in commercial instead of residential?  


If I decide to move my business to a more visible area, would I have issues lending from a bank? If I'm moving the main "tenant" out of the building, would the bank see issues with no/little income coming from the office building?  


Thanks.
[{"id": "i0r9pgm", "text": "Depends on the valuation of the office building. I don't know about Seattle, but the office sector in general is cratering.", "replies": [], "depth": 1}]