Make sure each party knows what their responsibilities are and be clear on expectations.

But, it's not a true negotiation in that either party can say whatever dollar amount they want, and then they have to wheel and deal and come to an agreement. 

If both parties agree on terms (price, etc), you could always hire a RE attorney to go over with and explain the contract to the seller before he or she signs for probably a 1/2-1 hour consultation.

However, the land can be owned by the self-directed IRA and then rented to a third-party provided it is not your parents or theirs children, for example. 

I see how leverage on my end would work, but I did not know the new lease could be replaced assuming both parties agree and sign on the dotted line.

Ive been to seminars, groups, and social connecting parties.

I expect that we will use it for a family holiday party, probably one weeks’ vacation a year and a few weekends when we can get away.

If they try and place a lien on the property and you have a signed contract by both parties documenting the scope of work in it's entirety, then you are in the right (as long as you paid them).  

Third, the numbers.After that, you have things like the neighborhood, the local market, the distance from where you live, etc.

Toughest part is finding the deal.