Once you understand that, then you will have a better understanding of the type of investor you need to bring to the table.

Found this small 1500sqft warehouse with 12' clear-height doors, open floor plan, open rafters and unique feel.

Good job.Next, they decided to go without either a hot tub or a game table. 

If you bring no funds to the table and are getting ownership  through sweat equity,  you earn that equity by doing the things you described: finding the deal, overseeing the rehab, ect. 

Used HELOC for down payment A unique property as the front side is a post office and the back side is a 2 bedroom house.

This property is unique in that I did not purchase it to be a rental property for cashflow.

I've gotten much better at finding great deals as well and feel like I'm leaving a lot of money on the table because of cash constraints.  

I used the first time home buyer tax credit and literally walked with cash from the closing table.

Heck, joint venture with a partner bringing an equivalent amount to the table and you wouldn't have much difficulty taking down something in the 20-50 unit range depending on your area.

Cost is only relevant to the seller, (despite what any realtor will say...lol)   A buyer will not pay more than they are willing to regardless of the costs taken on by the seller.so regardless of buyer paying closing costs or seller paying closing costs, thoses cost come directly out of the the money the money the buyer put on the table.