I think the first thing you need to do is to figure out what your goals are.

Also, what are your RE goals? 

I can counter with a higher equity share, but my goal was to go to the bargaining table informed and with some realistic expectations in hand based on what other developers get for their sweat equity. 

This is just my experience with HELOCs, I’m not licensed to give any kind of financial advice, check with your accountant or financial advisor to ensure you are utilizing the correct financial products to reach your goals.

Lets say you invest the 40k into your duplex and it allows you to raise your rents by $150 per side yielding you another $300 per month and $3600 per year.3600/40000=.09Is a 9% return within your goals?

Yes, our goal is to move to Beaverton in the spring.

I already work full time in another professional field and my goal was to look for a commercial/investment property for myself.

Meanwhile I am always looking and trying to invest elsewhere.Currently I am looking for:Multi famliy, or single family rentals in or around:Anacortes, WashingtonMount Vernon, WashingtonOak Harbor, WashingtonBellingham, WashingtonVancouver, WashingtonMissoula, MontanaVacation rentals around:Puerto RicoSan Juan Islands, WashingtonI know nothing about, but am very interested in wholesale property as well.My real estate goals are to eventually buy and hold a large apartment complex and  a large amount of vacation rentals.

My goal is to buy rental properties and to be financially free as early as I can but I'm reluctant to be financially free as early as 40 years old and im now 28 so i still have 12 years. 

You need to take into account your long term goals, your short term goals, your resources especially finances, and your risk tolerance.