bought this a couple weeks ago from amazon warehouse "like new" for $16. you can also check with gohastings.com, they often run a B2G1 deal, which can make it more affordable, assuming you're willing to buy a couple other games. might be worth it to check in with your local gamestop too, just in case.
its kinda frustrating, honestly, since i dont think its worth the price its going for... the art is really cool though, and i like the concept. i totally wouldn't mind if they made more of these. hopefully if you look around you can find it a little cheaper than what i listed, good luck finding it
Price goes up when a new MGS game comes out. It happened while MGS4 was soon to be released. You can find them for cheaper than they're worth, but demand fluctuates. Expect the value of them to rise when Peace Walker comes out and MGS: Rising comes out.