Those prices are insane! $229!?
I had the same thing happen to my powerbook (and it was in a case I bought at the Apple store! sheesh), so I talked to the Apple repair dude at work and he looked it up on Apple's site and Apple only charges $96 for that part.
I didn't bother buying it since it wasn't that big a deal and involved a lot of work (you have to literally take every screw out of it to replace the bottom case), and now we can't buy parts directly from Apple any more (they changed their hardware certification stuff or something).
So I'd just look around for a friendly non-chain operated Apple authorized dealer in your area and ask them how much it would cost to get the part and/or to replace it for you.
If you're near Boston, MA look at
The Computer Loft as they seemed to only deal in Apple computers and had a pretty nice website. I haven't even talked to them about it so I dunno.
If you decide to only get the part and do the repair yourself, make sure you get ahold of the PDF that shows all the screws and stuff you have to replace, since you have to take the whole dang thing apart.
Good luck!