On wholesaling that is just transactional real estate with income that is taxed at the highest level and to be successful at it one needs partners or access to pretty decent amount of start up money to afford the marketing it takes to get your leads.

You probably have heard to join the local REIG as what you will find from the courses advertised everywhere anymore is that they offer general information that in many cases does not fit your market or state requirements. 

The market rent needs to be around $1,800 per side and no more than 2k a month (depending of finshes) I'm having a hard time getting someone to nail down a price on construction cost.

I live in a cheaper market with a lot of sub-75k properties.

They literally wrote the book on midterm rentals and cover how to analyze markets.

Yes, Builders have a lot of margin that they are working with typically because they set the market and manipulate the home prices.

With the economy and market as they are, should I continue aggressively paying down the HELOC to potentially borrow against again or should I just pay the Interest Only (IO) payments and seek other funding at the current day higher interest rates?

It is not on the market but I have an investor who is interested in purchasing it. 

New constructions in the neighborhood are selling for a significant amount above construction costs (double or more the market value of the land).  

The facebook groups are a great place to find mentor programs and such in your local markets