Tons of labor & laundry expense.  

In 18-months the damage will be somewhat limited and {hopefully} will not have had the opportunity to permeate the subfloor and structure {though that is a possibility} - you may just get away with a lots of cleaning and replacing finish flooring (like carpets).The longer they stay, the more expensive the repairs will be at move out.

Even my $3,360/yr maintenance budget feels a little low to me based on the rehab to be done on the first floor.Now, when I plug these numbers into the calculator referenced above (including an 8% vacancy and $280/mo for repairs and maintenance), I can see that you'll have monthly expenses of $1,640.  

I'm considering starting an LLC that I can run rental income and expenses through for the main purpose of starting a retirement plan (probably a solo 401k) so that I can start socking away some income into a tax deferred account.

East Rock appears to have some serious potential East Rock is a wonderful neighborhood but very expensive to get into.  

The stucco on house is old and in bad shape so probably needs to be removed or vinyl side over it.Question: If I decide to an an offer how much should I budget for repairing this and how complicated and expensive will this repair be.

I'd like to self-manage the first rental as a learning experience but would eventually plan to transition to a management company, so the numbers have to make sense to cover this expense.  

The $840 mortgage and expenses are covered nicely by $750 in rent (housemate on my primary residence) and $1550 in gross rent on the duplex. 

Issue is Electric vs gas :(  utils will be expensive and you need to address that at lease orally with the prospect.

I think I have the swing of the expenses finally, but I am confused about the amount I've invested.