Neighborhood-specific agents told me to list it for $50-75K more than I actually did.

As realtor/investor who specializes in working with investors, I can be your one-stop shop here connecting you with home inspectors, general contractors, and property managers all of whom I know and trust.

Can try to reposition to Class B, but neighborhood may impede these efforts.Vacancy Est: Historically 10%, but 15-20% should be used to also cover tenant nonpayment, eviction costs & damages.Tenant Pool: majority will have FICO scores of 560-620 (approaching 22% probability of default), many blemishes, but should have no evictions in last 2 years.

You can find 2x1 duplexes in the metro for under $300k excluding prime intown neighborhoods and expensive areas of Gwinnett & Cobb county. 

Im wondering if it would be better for me to wait until I have the money in my bank account for a down payment, or at least another paycheck in the account (paid monthly) before I start shopping around for pre-approval letters.

Look at property values, trends, and neighborhoods to identify opportunities.5) Create a Budget: Determine how much you can invest, considering all associated costs like down payments, closing costs, and maintenance.6) Build a Network: Connect with real estate agents, investors, lenders, and other professionals.

If yes, which neighborhoods is relevant?

The purchase prices, lease rates, asset quality and neighborhood safety are not aligning. 

There is a long LONG list of towns, neighborhoods, markets that have had a downfall and NEVER recovered.

Let's not pretend software widgets are 20 thousand square foot shopping centers...