Since these costs have already been incurred years ago, do I still take them into consideration?

One thing is certain as an investor you don't want you money held up in the court confirmation process for a few months.Your interest is in purchasing the probate property from the Executor/Administrator as long as they claim IAEA powers and filing Notice of Proposed Action.

Basically, stop wasting your time pining over a house that you sold and got money for and take your money and buy something else and make it better.Emotional attachment to real estate is a money pit every time.

I owe 400k on the house, so about 300k worth of equity just sitting there.1.I can get a HELOC and use the money for BRRRR, the problem is, I can't find anyone that is giving out loans for investment properties, I have tried most banks, up to PenFed, nothing so far.2.

Did you keep the buyers earnest money deposit? 

Secondly, why would anyone PAY them to sell their money?

You will get tough skin, and if you can handle sec 8 you can pretty much handle any other tenant. 100k unfortunately won't get you too far in many places; BRRRR is fine but unlikely to pull out 100% of your money.

I am planning on being married in the next year and a half and my partner and I are currently saving up money so that we can start investing in real estate, we are targeting fall of next year to start and should be able to have $80,000-$85,000 to invest.

@Aaron Dominy   Building supply chains have eased considerably in the past 2 months, thus the time-frame to build in Galveston has shortened.

There is major money involved in the right answer that impacts not only monthly cash flow but the overall value of the building.