Where is a good place to get a replacement laptop battery cheap?

[xvszero]

My battery has slowly been holding less and less charge over the years and then yesterday pop... stopped working, period. I think it is the battery, anyhow.

Battery is this model: sony vgp-bps9/b

I'm looking online but I'm either finding knockoffs or places trying to charge me close to $200 for it. Blah.

BTW does each Sony laptop only have one potential working battery, or are there various battery models that would work?

[sr developer]

If you know someone who works for accenture and if he buys it for you it costs 1/2 the price.

[RaCo]

Here check it out: http://www.new-laptop-battery.com/Sony/Sony-VGP-BPS9-B-battery.htm