In that case you might save taxes building with them.

@Collin Hays That's the trend I'm starting to pick up on watching the market.

Might coat you $500 or more for a hour but will save you a $15k bill from a contractor who simply sees a easy way to make money off off you! 

You essentially save 20% on materials for the markup.

I don’t know if I should invest in the Jersey market and put maybe 20-50% down on something, make less cash flow and make more appreciation, or every two years or so maybe buy something fully cash (my own $) in the Midwest let’s say 5-10 units and make more cash flow with no debt as with the income I make I can just save and buy more, don’t necessarily need to leverage in some markets.

Remember to save some money for capital repairs.

A hybrid approach could also work—perhaps using a HELOC for reserves while saving the stock portfolio and 401k loan as backup options for future opportunities.

This can save months of headache in MA trying to evict 

I started my first business when I was in my early 20s.

Why not just save for the downpayment and work on increasing income to qualify for a traditional loan?