I'm not disagreeing with you completely, but your 50$ each is a bit optimistic. can I get that price any time? not now, when I go to a website and try to find something for tomorrow its 109$ (Expedia).

the travel time listed is 1:30 compared to 2:30 (from numbers I heard) so you do chop off one hour of ride time.

however, air port security checks, being kicked from your seat, sf airport not directly in the city, the one hour starts to mean a whole lot less