Hi Mike,
I've been thinking about the exact same thing, I'm finding it hard to justify that extra cost of the f/1.4...but then again.
If you keep yourself warm at night by burning wads of money in your cumbustion heater (old notes, not the 'new' plastic ones, of course) you could even get the old supposed 'holy grail' of lenses the 50mm f/1.0. It has been discontinued and now sells for more than its original cost of US$3K, I saw it with my own two eyes on American ebay last week going for US$5,990!
Check out some photos, particularly the one of Niagara Falls:
http://www.photo.net/equipment/canon/50-1.0.html
Here's a couple of forum type websites on the subject if you've a couple of hours to spare to read them:
http://www.fredmiranda.com/reviews/s...ort=7&thecat=2
and
http://www.photo.net/equipment/canon/50-1.4
Hope they don't add to the confusion of choice.
Cheers,
Michael