Well $450 ain't gonna buy you much. I mean, the latest Nvidia cards cost more than that just for the GPU. So if that is your total budget you might have to go old-school. Meaning with the old Nvidia legacy drivers on Windows XP and a vintage card. You can get a 7900 GTX for like $20, and that should be able to run older games like Half-Life 2, Unreal Tournament 2004, F.E.A.R, Tomb Raider Anniversary, etc. Then you will need a CRT monitor, mostly any will be supported but look to see if you can get one that can hit 120Hz at a decent resolution. Shipping would cost a fortune, but you might find one on craigslist locally (or maybe you have one laying around). Shutter glasses (like the generic DLP rebrand of the ELSA Revelators) will cost you about $75. CPU/Mobo/RAM is not as important, but you still need something capable. P4 2.4Ghz w/ 2GB RAM is probably the lowest I would go (I used to run that and had a lot of fun playing older titles). If you want to go more modern, then you can probably cobble something together using AMD parts for a decent amount. I found this after a quick search for $379:http://www.newegg.com/Product/ComboBund ... =u00000687
However you would still need to add a video card, like the Radeon HD 5670 for $79, which would bring you to $450. However this doesn't include any sort of 3D display or glasses, etc. Since its a total AMD rig, then Nvidia 3D Vision is not an option. You could still go for an old CRT with the DDD/IZ3D drivers if you use interlaced mode (but you will also need shutter glasses that include a "line-blanking" compatible dongle). If you want to go really cheap, than anaglyph is always an option. I recommend the Pro-Ana glasses ($10). For any modern 3D solution you are looking to spend like $300 off the bat, probably closer to $500 for the display/glasses combo. I mean, you can probably find the IZ3D monitor for like $150 on eBay but it hasn't exactly got the best reviews. Still, you are not going to get much better for the price. Then there is the VR920 for around $350, but you will then need to buy the iz3d drivers ($40) and the experience probably isn't as great as a 3D monitor. Then there is the Nvidia 3D Vision, around $500 for the bundle (but remember you need a Nvidia card which will cost more and it only works with Vista/7). If you want to go the Nvidia 3D Vision route, then there are also some 3D projectors starting at $350, so that could be an option. There is also the Zalman Trimon 3D monitor, which does work with AMD GPUs but costs around $500+. And you could always get a 3D HDTV, but then you are going to spend $1000+ just on the display. So any way you look you are going to be spending a lot more than $450, even if you can build a rig for that price.