Unless it is a lifestyle decision I find it a risky proposition

What interest rate would you think is fair for that proposition? 

Be able to clearly communicate what you are trying to do and why they should want to do it with you, also known as a value proposition.

What is your value proposition to them? 

Coming from a two-decade long career as a marketer - whether you want to call it "your why" or a Unique Selling Proposition or a Point of Difference - it is the key to all marketing for every company.

If the lot is in Devonshire or in the San Carlos Hills, it could be a very expensive proposition as the lots are so sloped there.

@Alex Owens I don't think it's an either or proposition.

First of all, I have a interesting proposition that I came across recently in St.

Merely to explain that foreclosing on a borrower is normally a losing proposition for a lender, and is not the end goal.  

That's an extremely risky proposition.