Wow, I literally just bought this same battery. $86.95 from pc-nu.com and free shipping to boot.
here's the direct link to the product page if you want to check it out:
PC-Nu, your source for quality components at budget prices! Laptop/Notebook Batteries! Power Adapters! And More! - High-Capacity Battery for Dell Inspiron / Latitude / Vostro
you can even see my review i just wrote at the bottom haha (Ted is me)
i bought the battery weds. and just got it yesterday LOL.