My two cents worth after returning to the sport after a 20 year hiatus:
1) Don't get in a rush, try as many bows as you can and figure out what draw weight and grip style works for you. You will find that trad archers are generous to a fault and you will not want for opportunities to try out bows.
2) Ditto on what was stated in previous posts. If you have to spend 450 bucks, you can with no problem. But you can find excellent deals on the classifieds here and on a couple of other sites. If you have to have a new bow, I think for under 325 you can buy a brand new Maddog bow or a Quinn and you'd still have dollars left over for arrows.
3) Hold a few dollars back. Matching arrows to bows runs into some money as do strings, and bits of stuff to put on the string, and a different hat because you can't shoot with a baseball cap on forwards, and a good knife, and postage to have all this stuff shipped to you.