Digital SLR camera question (upgrade)

[househead]

I'm asking this for my wife since all the photography forums she browses are full of snobs and meanies. Figured I'd try my luck here since everyone here is cool.


"i have a nikon d50 which i love but since i'm getting more into photography i was wondering if it was worth it to buy a better camera (looking at the d300) or just buy better lenses. does the camera body really matter all that much?

i would love to have something with a higher iso setting for low light situations, currently mine only goes up to 1600 and basically i never use anything over 400 because after that the photos look way too noisy. i know that the lens matters most but should i even bother putting a nice expensive lens on a d50???? "

Thanks for any help or recommendations.