Reacquire property sold involving seller carry

Considering selling land to a developer with a seller carryback.  Doing my homework now to know what assurances I will have to eventually recoup my money/property in the even of a default.  I'm working with atty to prepare promissory note/deed of trust.  

Should seller not pay 2nd balloon payment portion 2 years after 1st payment, I would send notices and they would have 90 days to pay.  After that, it would go through a nonjudicial foreclosure process and by law would be put auctioned publicly.  Given that there won't be any other lienholders on the property other than myself (in the sale contract), would I get to set the reserve price for the auction? Could I set it higher than what is still owed on the property in hopes of simply re-acquiring it? Or would I have to kick in more of my own money to outbid someone else in order to reacquire property if their bid was equal to or greater than the debt owed?  Thanks in advance.