The house right across the street was just purchsed for $75,000.00.Is this an opportunity for an investment property that can save my parents from having to move? 

I drove that street for that deal you are talking about and it is a horribly bad area, probably top 5 worst in the city that I've seen.

You are right down the street from me here let me know if you want to grab some Great Bar B Q if you are ever in town!!

Example: 123 Carter street is a triplex on Zillow.com. 

The building would need to be demolished of course.The lot is on a street with only SFH and one block away from the business area of the neighborhood.

Similar duplexes on this same street rent between $600-675 a month.

I am looking into buying a duplex in a strong rental market in a great location but there is a new multifamily development that is scheduled to start construction later this year on the property right behind the duplex (line of trees behind to separate but traffic would go through street in front) .

Network with investors that are local to you to expedite your search or start beating the street and knocking on doors until you find the right people to work with.

Guessing will get you out of this business before you even get startedtaxes can be found on the tax card, go to the tax assessors website or just type in 123 main street, city, state zip tax card.

There are better streets than others if I needed to tough it out for a year in half a duplex I could do it.