Just for the record the folks who make the CryEngine (aka Crytek) have said many many times that they designed the engine from the ground up to scale the game as needed to make the game playable for the PC its running on. One of the recent quotes is "Crysis scales 2 to 3 years back and 1 to 2 years up, so its 5 years of scaling." This means that if we take the pessimistic view of this statement, your computer would have to be considered high end 3 years ago to play crysis.
So pretty much if you have a decent GeForce 6 series card or better you should be fine to play the game at low settings. Minimum specs are not expected to produce super results for any game and its no different with Crysis or even UT3.
If you want to constantly play the newest and the best its going to cost more. If you are content to stay with hardware for 3-5 years making minors upgrades when/if needed you can get by at a pretty reasonable price considering the other functions of a computer. This is no different than consoles, except you get choice with the PC. With a console you are locked into the hardware until the next generation, but you get development directly for your hardware as compensation for that loss of freedom.
As with most things in life its a trade off. You basically have three choices...
1) Console - Hardware locked in - Hardware Specific Development as consolation
2) Average PC - "Average" Hardware is a moving target - Hardware scalable as consolation
3) High End PC - Constantly Purchasing New Parts (12-24 month cycles) - The best of everything as consolation
If I could afford option 3 I would go with it instead of #2, but as it is I do just fine with 1 & 2. It's a personal choice so their isn't really a right answer...
