BMW Repair: Wheel noise, possibilites, cheers

Question
My 2000 328i has front end noise I suspect may be the wheel bearing.  How long can I drive until I need to repair and is this something I could do myself.  The last time I had a front wheel bearing on it replaced it cost over $300.  Also if it is something I can repair where do you recommend that I purchase the parts?

Thanks,

Answer
it can be done at home but keep in mind that you may need a puller to get it out.  
what makes you think it's a bearing?  does the wheel yaw back and forth when pressure is applied to the top of the wheel (osscilateing pressure with your foot).  Other possibilites are allighment or a bushing.
-cheers