Does it usually cost money to have a contractor come out and do this?

All you need is a team, :) Well and money LOL,  Lol, money I have, the team is the roadblock.

I considered private money for purchase and rehab and refinance at a later time.

Both are making money and have reasonable cap rates, a bit lower than I would like, however, not horrible Imo. 

think about how much money that would be, almost nothing.

-I hear condos are now charging outrageous amount of money for association fees and costs and people are selling their properties on account of this.

**This is my favorite** Buy the rental with seller financing, private money loan, or commercial loan in an LLC.

I will assume his loan and he pays me his mortgage, plus a little extra.

If you pick your JV correctly you can make a lot of money.

No matter where you choose to move, you are perfectly set up (if the money works) to house hack with your wife in one unit of a two-family and then to mid-term rent the other unit because of your medical connections.