(A duplex in the same area in great condition would cost $500,000)I have two questions: 1. does this sound like a good investment?

This what they did: Develop an accurate budget for spending in retirementUnderstand the options available through Medicare and the cost of those optionsReview Social Security benefits, and identify the optimal time to begin drawing benefits to maximize the likelihood that your financial plan will be successfulUnderstand the mechanics behind taking portfolio withdrawals to support your financial needsAssess the impact of a potential long-term-care need on your overall retirement plan

In addition, lenders will ask for this information if you intend to finance the property.Review the condition of the property to determine if there is deferred maintenance.Review Yelp and Google for any tenant reviews to understand any issues residents might have with the property.

We’re very familiar with the ground conditions in San Antonio.

He approved the condition and rehab and we instructed title to get everything together for the final signings.Day 8 December 28, 2015 ~ We completed the files for both the buyer and seller.

I don't know what the condition or age of the property is, but being in what you have described as a bad area you should budget higher on the expenses to account for them. 

What is the condition of the property -- do you need to set aside funds for deferred maintenance? 

So, many people are asking $$: mortgage $3500, insurance $30, tax $1200, HOA $500, and RENT $3350 (2b2.5b TH in decent condition), not counting repairs/ maintenance/ possible vacancy. 

Seller likely knows the condition of the property.

Ideally you should be able to determine your target rent by knowing the rental market, looking at the condition of the units and estimating expenses.