We have retirement accounts, a small private stock market account, and an emergency fund. 

It sounds like you know how to avoid this in the future, so what to do with the situation at hand?

It is not really apples to apples, but generally speaking the more money invested the further ahead you will be eventually in the future, just because your compounding base is higher, regardless of where the money comes from - ie, 4 300k properties are 1.2 million on property, which is double the 600k property.

And @Kory Reynolds brought up a good point about recapture of the section 179 deduction if your business use drops under 50% in a future year. 

I am looking to buy into one of their offerings in the near future using a SDIRA.

Quote from @Yianni Hahalis: Hi all,I will soon be moving to Cleveland, OH and either renting or buying in the surrounding area with my future spouse.

I have a lot of other investing ideas as well that I hope to be able to use in the near future as well. 

I have $55K in the stock market at the moment and plan to save (and grow) the remaining in the stock market until I have enough to pay off the entire mortgage. 

Best of luck for your future!

Getting a FincenID makes it easy if you have more than one or expect future updates.