In CJ's last post (his best yet) he mentions 10 passenger mars landers. Does this fit within the parameters of the previous 4 passenger, 2500 kg payload landers? Easily.
Volume is no issue. If you've seen photos of existing Dragons it's obvious there is room for 10 for a short duration landing. Assuming each suited crew is 200 kg that leaves 500 kg of consumables. 50 kg each or about a week of supplies... enough to get them to a prepared surface habitat. They aren't going to stay in the lander any longer than they have to.
At $150m per lander which can bring more than 500 kg to the orbiting ship if needed that gives us a per crew cost from orbit to surface of $15m each. Add another $15m from earth to LEO and we only need an estimate for orbit to orbit (will update in a bit) to get total cost per crew.
$50m total sounds about right. About a third my former estimate.
[Update: 185 ton of fuel and supplies requires 3 FH or one BFR so let's call that $300m or $3m per crew. I'm going to stick with my $50m total per crew estimate.]