Let's say you buy with FHA 3.5% down and pay $500/mo in mortgage insurance, a few years have passed, and now you have 20% equity.

You can do a simple web search to find brokerage firms that will hang your license for a flat fee verse a % of every sale/purchase but you won't get much assistance from them and I am not sure exactly how "legal" all that is.Other things to consider, 1) there is a fee to have access to and be able to list on the MLS, 2) I think the state requires you to carry or it would be a very good idea to carry Errors and Omissions insurance commonly called E&O insurance 3) if you plan to tour properties, you will need to get those electronic keys that agents have and I am guessing there is an annual fee associated with that.Those are the big ones I can think of off the top of my head.

Based on price of 1.75M with rents at 12k, highly unlikely you can get 5 CAP even with a near new building considering property tax, insurance, utilities, vacancies, property management, etc. 

You did not include Insurance.6.  

I’m looking for recommendations for insurance companies/agents and policies to provide a quote for 4 plex in Grand Rapids.

Landlords must be very hands on to insure issues are reported early and that the tenant is respecting all community regulations.

Do you get a Landlord Insurance Policy IN PLACE OF a Homeowner's Policy, or do you get both?

Or would it just be the monthly mortgage amount included taxes and insurance?

Until you have quieted title, you will probably not be able to get title insurance, either, because of the possibility of outstanding judicial redemption rights even after the tax deed date. 

Here is how I see the deal.Asking Price- 600,000# of units- 13 Gross Operating Income- 71,820less Taxes- 3087 Insurance- 2310Repairs- 6875 (added 25% to estimated price, )Utilities(common area)- 400Misc(pest, snow,landscaping)-2300Net Operating Income 56,848lessMortgage Payments 46,800Cash Flow 10,048Now I will not be offering $600,000 but really wanted to check with some of you experts to make sure I'm not forgetting anything.