You have to consider a lot of variables (like rental markets, capital reinvestment, tax advantages, etc) to keep your bottom line returns up.  

I am choosing to save up some capital until I can afford to handle mistakes, before I jump into a 6 figure decision.

I have particular interest in Wholesaling properties to build my own capital, once build I want to transition into multifamily deals.

I lived in the rental for three of the past five years, so I should be able to take advantage of that $250k tax break on capital gains, which should be plenty to cover my equity gains.

Because I believe the cash flow this building will kickoff will feed me for a lifetime.And...30% in capital gains as tax and a $6000 prepayment penalty did not excite me.1031 exchange may of worked, but, it sure is tough to locate a replacement property that would suffice.Thoughts?

Additionally, only my aunt's third appears to benefit from the 250k capital gains exemption.The house has appreciated approximately 300k in the last 16 years. 

You might be able to more deduct the expense in the same year as well under different code( sec 190) see below.Remember, expenditures unnecessary for compliance with the Americans With Disabilities Act of 1990 (ADA) are not eligible.If you spent more than 5k in both removing the barriers and making changes for the compliance,  you can deduct other expenses up to 15k rather than capitalizing and depreciating it. 

How did your duplex sell and where did you decide to transfer your capital?

Avoid short term capital gains?

This cost should be used in the beginning as part of your initial capital.