I'm not sure where you were looking for the 5D Mark II but you can get the body only at B&H for only $2,699.95 and they are a very wonderful place to do business with.
Those are probably our Canadian prices. Our dollar is probably strong enough that ordering from B&H would save us some money, but I believe you then have to deal with any warranty work in the US rather than Canada.
I have a Nikon D90 (and an older D50 I keep around just in case) I primarily use my Nikkor 18-200 because it is so versatile but I do prefer the 50mm 1.8 if I'm at home. Now you ladies have me curious about this Tamron lens!
I've got a Rebel XTi (desperately saving to upgrade!!), 50mm f/1.4 that I'm addicted to, and the Tamron 24-75 f/2.8. All stuffed in a Crumpler bag. The Tamron is a great everyday and travel lens, but whenever I can it's the 50! I've got a few things on the wish list (besides a new 50D)...a macro lens, wide angle, bigger zoom and this handy reflector. Oh, and the Instax Mini for fun.