[Porsche-O-Phile]

I thought tax assessments were based on appraisal value, not selling price. . .

Appraisals (although they're supposed to be objective and more-or-less consistent) are all over the map too. What I'm finding is that certain individuals want to deal with certain appraisers. A seller probably has an incentive to deal with an individual who appraises a bit high, since he can then justify jacking up his asking price. Similarly, the seller would prefer a "low" appraisal both for tax purposes and for negotiating purposes.

So, in absence of anything better I'd say it's not a bad idea, although I still bet there's a pretty big spread between negotiated selling price and appraised price in a lot of cases. . .