When I look at comps, I check the ones that are currently for sale and recently sold, and try to compare and contrast all of the technical aspects of the property (the ones listed in that article) as well as the fluffier stuff like aesthetics. 

I believe if this vacant building is like most your estimate of rehab is way understated.It's not just the interior of the property but all the exterior components and additional interior upgrades the county or city might require for code compliance.If landlord pays water or other utility with current setup design then go 60% costs annually instead of 50%.

@John HarrisonHUD FMR are the MEDIAN rent are not by design and definition comparable to any rent that is in the top 50% of rents charged in your area.HUD FMR are ONLY comparable to rents in the LOWER half of rents.

If you are designated a dealer, then the interest income will be treated as ordinary income.  

Roofs are installed to a design wind speed of 75 mph even in Maryland I believe. 

You will lose money investing in tax certificates if you are unaware of prohibitive species designated areas. 

If it makes 10 after expenses it will be good like I said weddings there are 6k and up one of those a month will be great I will get a web designer to make me a great website once I get it cleaned and landscaped.

The driving factor behind this seems to be a 15% property tax on Foreign money, which appears as if it was designed to specifically target Chinese money in the market.

A friend of mine works for an Architectural company and they're developing a Tiny House concept and their model home is almost complete, but they need a structural person to look at their design.

Attending their conferences is a good setting where you have designated social time to ingratiate yourself to them.I also advise registering in every state you intend to market in, have an expert law firm prepare your offering documents etc.