am working with them now and had the first policy (with Spinnaker) cancelled for nonpayment/late payment so we rewrote another policy (with Millenial) and having the same payment problem again but at least they are communicating that cancellation is coming. they want me to pay by credit card over the phone so the payment wont be late and cancelled again. but when i go to mycoverageinfo.com to check on status it shows its been paid.

What would standard down the payment be? 

With $100k down it’ll probably be slightly negative cash flow.

I paid cash and roughly 25% of retail value. 

I'd look at the closing docs for something related to the pro-ration of expenses etc and see if you have anything there that could be a clause you point to for them to cover those payments. 

You know those signs that say "we buy houses for cash" call them and say you are investor looking to buy a flip. 

Your payment went up $1,000/mo but the taxes only went up $5,200 which would be less than $450/mo.

One thing to be aware of is the FHA multifamily self-sufficiency calculation which determines if a property can generate enough rental income to cover its mortgage payments.

Personally, I think I would stack some cash for a year or so while I did this. 

Also, if you buy using a hard money lender or cash, Zach Starnes can do re-fi's off the appraised value shorter than the typical 6mos and then you might not need any money down if you buy at the right price.