That is a good point, but when you consider operating costs (just fuel, ignoring maintenance), the S85 is MUCH cheaper...
I think that math works out well, and considering I was thinking about an A6 or 535, the S85 is a no-brainer. Same price, better car.
Maintenance is one of the things I did consider. If I got a P85 or p85+, I'd pretty much have to get 21s, and tire cost goes way up. I'd also have to get air suspension, which has potentially more long term maintain cost (I plan to drive my MS for a long time ), etc.
I totally agree that the model S cost is really not bad at all when factoring in rebates ($10k in CA), plus fuel and maintenance savings. It's definitely cheaper than any other car that is even close to as much fun to drive...