Apparently, not only did they sell at a loss, I didn't get any money back at all and they claim I owe them an additional $40,000 for "renovations" despite no work being done to the building at all. 

The next 2 offers started a bidding war I got over asking with inspection for information only . 

I didn’t expect them to cashflow when I got started.

Without a cost segregation you depreciation the building value of your property across 27.5 or 39 years.

They were referrals and the business started to grow simply because I had a competent team that was responsive and looked out for the owners' best interests.

Quote from @Mike Levene: Hi @Chris RojasI started exactly the same way (with a triplex not a duplex but not important). 

Is just the fact that no garage could be a no go for some buyers enough to build it even if it only raises the value by the actual cost?

In reality, at the start of an investment you don't know exactly how the investment will perform.

I have helped hundreds of investors execute 1031 exchanges and build diversified portfolios across various excellent markets, all while using just one property management service.

The building value of the rental is written off across 27.5 years.