Only noticed your post this evening...
I'm probably going to get a D50 in mid-August. I've been comparing prices all over the place lately and it seems that Simon's indeed has the best prices:
D50 + kit lens: $849.99
D50 + Kit Lens: $799.99
D50 + Kit Lens: $789.99
D50 body + Sigma Lens: $789.99
I've never shopped at LL Lozeau, so I can't say anything about them.
Dumoulin & Japan Camera has them in stock (at least, they did last Friday); Simon's is "temporarily out of stock" at the moment.
I like Simon's Cameras a lot; I've shopped there a number of times over the years (more often years ago when I was a student). Recently I bought a Raynox DCR250 macros lens (for my Panasonic FZ20) there and found the service truly excellent. All the staff at Simon's know what they're doing, they know cameras, and I'd much rather give them my business than go to another store. It's kind of special to walk in that place as I'm sure you will agree. Love it.
I'll only consider going to Dumoulin or Japan Camera to buy the D50 if Simon's is still out of stock at the very moment I want to buy. Between the two I'd prefer Japan Camera as the camera would be $10 lower - and their sales staff are probably more knowledgeable than Dumoulin too (and definitely less annoying).