...the 50mm f/1.4 is something i'd rather get first if getting both is out of my budget.
Keep in mind you'll pay $200 more for an additional 2/3 of a stop compared to a 50mm f/1.8. Yes that makes a diference, but f/1.8 is nothing to sneeze at. More importantly, when you stick a 50mm on a digital camera (excluding those with full-frame sensors) you may be disappointed. Even with 35mm SLRs I wasn't much of a fan of the 50mm. Taking the cropping factor into account, it "becomes" a 75mm which is not a particularly useful focal length for general photography. It
is a great lens and I've taken some excellent photos with it, but it's not the right tool for me. The right tool is probably a 17-55 f/2.8, but I don't own one... yet
My advice is that the two bills might be better spent elsewhere, and a 50mm f/1.8 will give you more than a taste of what a wide aperture brings to the table. Also, you mentioned getting the 50mm first... I wouldn't do that. If it's the only lens you have, your snazzy new camera won't be nearly as much fun! Chances are, shooting concerts will only be a small part of your photographic endeavors.
-Frank