I was in love with micro lending until the account hit 5 digits and I started to get nervous, so I opened a Prosper account to build that and when that hit 5 figures I started saving for my first rental. 

This attracts a lot of out of state investors who think that the low barrier to entry and high tenant pool equates to high cash flow at double digit rates as it would appear on paper. 

I own a digital marketing agency (high stress for sure), make 7+ figures, and have a family of four to support (my wife doesn't work).

I'll go back and edit that now

. $4500 seems like A LOT of money to transfer our digital plans into CAD (the contractor already built-out our design ideas on his laptop's software) and have an engineer ensure we're using the right beams in the right places.

EDIT: My ideal timetable is 1 - 2 years.

My apologies but their is a serious typo in my initial post and I am unable to figure out how to edit my original post.

Unless you can provide your private lender with secured double digit returns, I agree with most, your dad may have to do this on his own, or simply have you intern with him on this deal. 

Personally I would invest in a fund with an 8%+ preferred return with equity split that pushes the realized return to double digits before I would pay off that debt.

Hmmm...Edit: yeah, I don't see adding substantially to the value. 40k would really be tops for this property in this area