FMV for divorce purposes

Only as much latitude as the tax auditors will give you! Get an independent appraisal according to industry standard practices and deal with it. Or agree in advance to do two independent appraisals and average them. Any adjustments you make in self-valuing the unit or overruling disinterested parties will be questionable and difficult to defend.

Your broker should do a FMV letter for you as a courtesy. I guess if it's acrimonious, you could each get a letter from a different broker and then take the average.

ali r
{downtown broker}

If it's acrimonious, the respective lawyers should agree on the method to be used and the common terms of reference (how square footage is to be measured, for example). "Your" or "His" or "Her" broker may have an ulterior interest in the potential future sale of the property, and so provide a biased value. The truly acrimonious situations will require independent and unconflicted appraisals (i.e., broker has no past or future connection to any party in the transaction).