I built some like that out at Hood River Oregon and they were super popular but better looking than those but still had shed roofs etc. was wondering if this is like a gold rush area maybe instead of mining the gold you sell the pots and pans to all the tourists ??? 

If the sales price is $850k you will need significant down payment to carry the DSCR loan on $5300 current rents...check in with @Joseph Chiofalo  as DSCR loans 5+ units are typically a bit more difficult to place as well. 

i think carrying costs like interest are something investors love to omit. 

For example: If your credit limit is $500, you want to carry a balance of $45.00.

I also know that doing a 1031 exchange will enable us to carry all of the proceeds from the sale as a deposit on a new property.   

So, even if 1 property has excessive expenses in a given year the other properties carry it.

The cost of purchasing the house, rehabbing the house, and extra reservea and carrying costs during that time.Take a nicer part of Baltimore, I'd probably want $350-400k liquid.

Also a seller concession is a good tool to reduce closing costs and carrying more than necessary on the primary. 

Agents and wholesalers will be your best source of deals, treat the good ones like gold and they will bring deals to you, instead of you paying for marketing.

This is very early to say but yes, I think one of the next "gold rush's" for investors is in the development/re-development of these communities.