Man, those prices are high!
I suppose where you live could be why they're so much higher, but to add to the mix, here's the price of my PC, which is about a year old. It runs Crysis max without dipping to a point I'm bothered(so nothing choppy.) at 1600 x 900. I need to buy the newer one -- which runs better from what I read, I've just been busy with other games.
Intel Core 2 Q9450 4 x 2.66 ($279 when I bought it, now I can get a 9550 for $169)
PNY GTX 275 ($199 Bought it last month. Didn't really need to jump from a 9600gt, but the price was really good.)
Intel DP35D ($99 when I bought it. Most stable board I've owned and also the cheapest!)
Corsair HX 620 PSU ( $139 )
Corsair 4 gig DDR 2 mem. ($110 when I bought it, I can get it for about $70 right now)
Antec Case ($80 on sale when I bought it, actually costs more right now.)
I didn't need a HD, but I looked at current prices. A 500 Gig Segate is $60 at Microcenter. I also don't need an OS since I have XP64 Pro, but I noticed that an OEM copy of XP Pro or XP64 Pro is $64 on Pricewatch, but not sure what its deal is. Prior to Vista bombing, I recall seeing XP64 Pro for less than $30 online.
Anyways, a PC similar to mine, just with a faster CPU, will cost about $950 to build including tax here in California.