It's $327 US at Newegg. I got it for $399 CDN from Ncix but it's going for as low as $389 CDN over here in Canada. I think this is pretty cheap for a 128 gig SSD but it's definitely much more expensive than a normal hard drive.
It arrived the next day after I ordered it so I'm surprised at how fast it was delivered. Some initial impressions so far:
Battery life is INSANE on this thing. Did a fresh install of OSX which took only about 15 minutes and with display at 40% brightness and surfing the web I'm at 73% battery life with 4:43 hours of battery remaining. So at full charge that's about 6 hours of battery life. I notice the battery meter doesn't jump around as much as on the stock hard drive either. With the hard drive it would ping pong around when you wrote something to the drive. This SSD stays very constant in terms of power drain. It's also dead silent, runs cooler, and let's me do silly stuff like surf with the machine sideways in bed
Apps load super fast, usually before a full bounce on he OSX dock - even iTunes which used to take a few bounces with the hard drive. Big web pages load faster now too. I was surprised on that but it seems the hard drive was actually limiting how fast "blog" style news sites could load since there were so many pictures/text/comments to grab.
Benchmarks you can find all over the place, so haven't done any yet. The only "benchmark" I did so far was to run the Windows Experience Score on bootcamp. My HD got a 5.2 score before and now it's 6.9.
Obviously everything feels much snappier and faster in normal use. Definitely worth it if you have the money. The only strange thing was that you have to use Disk Utility during the install to make a "GUID Partition Table" before OSX will load. You only have to do that once and never again since the drive comes by default setup with a Master Boot Record for Windows.