Do these places seem reputable to buy online? Because the deals are way better than a regular Apple dealer.
http://eshop.macsales.com/shop/powerbook/battery/ibook-g3-g4-12inch/
http://www.battdepot.ca/model/apple/ibook+12-inch+dual+usb/lap014.aspx
If you can get the cells, you can repack your original battery for much cheaper. Open it up and take a look at the cells in there – you can find them on eBay and other places.
I once repacked an iBook battery for under $20. Though I suck at the soldering, so I got our own HTMF member Jase to do it for me.
I’m not going to even try. I saw a video on it.
Seriously, there’s gotta be a soldering nerd around. Someone in one of your classes that you could get to do it ? 
Jason did it for my battery, and it worked just fine. You can find the cells at hobby places too – they’re the same kind that people use for remote control stuff.