the SM57 is a good mic for screamers (or folks with really strong pipes) so don't discard it when recording vocals.
In you price range (if I'm doing the math correctly)
a Senn MK4, MXL990 - and have it modded by Michael Jolie, ode NT1-a, Blue Yeti, AT 4040... etc
There are lower priced mics , and while 'bargains" there really is a reason some mics cost more- is it always justified??? not always, and your pre-amp has a lot to do with it
but if you're serious about recording, buy the best you can afford at the time of need. IF it's really just a hobby, buy whatever happens to strike your fancy (meaning who's marketting is the best!)