Geforce 9400GT and "High Graphics", being used in the same sentence? no, LOL...
depends on what you mean by High graphics I suppose.
if you mean everything on high with 4x or greater anti aliasing and 1680x1050 or greater resolutions, with newer games, then almost definitely no.
Price of the system with parts listed looks about right.
pricing for similar parts on newegg comes out to a few bucks cheaper.
if it includes a Power Supply (quality brand unit), then its a steal for the price, if its an el cheapo PSU, its still a good price, But I'd look at buying a new PSU to install.
with out PSU, its still roughly the same price range as buying all the parts new and assembling your self.
Price wise, its a good PC, but the PC case is the price killer (Coolermaster Stacker Series), for what the Case costs, you could get a cheaper one that will work fine (for whatever stupid reason they're using a MicroATX motherboard in an Extended ATX case design, Full Tower, lots of wasted space with that build)
Newegg.com - COOLER MASTER Stacker 830 Evolution RC-830-KKN3-GP Black Aluminum ATX Full Tower Computer Case - Computer Cases Newegg.com - HITACHI 0A38016 1TB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - Internal Hard Drives Newegg.com - XFX PVT94GZAH2 GeForce 9400 GT 1GB 128-bit DDR2 PCI Express 2.0 x16 SLI Supported Video Card - Desktop Graphics / Video Cards Newegg.com - ASRock G31M-S LGA 775 Intel G31 Micro ATX Intel Motherboard - Intel Motherboards Newegg.com - Intel Core 2 Quad Q8200 2.33GHz 4MB L2 Cache LGA 775 95W Quad-Core Processor - Processors - Desktops
total for those parts, your looking at $557-ish, another $30 or so in shipping.
so right around in the same price range.
for what your describing though, you'll want a better CPU (2.4 or 2.5GHz or faster), and a better video card, Geforce 9600 series or better, but I'd look at least at a 9800 series or better.
for a mere $40 more in price, you could easily put together something like this, that will be quite a bit more powerful, especially for gaming.
Newegg.com - COOLER MASTER Elite RC-331-KKN1-GP Black SECC ATX Mid Tower Computer Case - Computer Cases Newegg.com - HITACHI 0A38016 1TB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - Internal Hard Drives Newegg.com - BIOSTAR TA785GE 128M AM3/AM2+/AM2 AMD 785G Micro ATX AMD Motherboard - AMD Motherboards Newegg.com - BFG Tech BFGEGTX260896OCE GeForce GTX 260 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards Newegg.com - OCZ ModXStream Pro OCZ500MXSP 500W ATX12V V2.2 / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply compatible with core i7 - Power Supplies Newegg.com - OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model OCZ2P10664GK - Desktop Memory Newegg.com - AMD Phenom II X4 945 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor - Processors - Desktops
total comes to just under $635, not including any rebates, and shipping is roughly $5 or $6 (most of the items are free shipping products)
case is a mid size case, its plenty of room (I used to have one, I sold my old Quad core system parts in it to a friend, works fine)
Power supply is quality brand, plenty of power, modular cables, which come in handy for cases like this with not a lot of room for tucking away extra unused cables, simply just don't use those extra cables and have them not plugged in to the PSU.
CPU, is a much more powerful Quad core CPU, for only a bit more than that low end Intel Quad.
Motherboard supports all of AMD's AM series CPUs (AM2, AM2+, and AM3)
Video card is many many times more powerful than the 9400GT.
Hard drive could be changed out to a better performing lower capacity drive (500 to 640GB) and knock off $15 off the systems price...
Newegg.com - Western Digital Caviar Black WD5001AALS 500GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - Internal Hard Drives
Free Game with Video card, plus another free game with the Quad core, AND free 6 month PC mag subscription with CPU as well.
Realized the original link in your post is canadian, Newegg is up in Canada now too...
so didn't factor that price in canadian dollars, its a tad high in price, but again if the PC comes with a quality PSU, or factor in labor for building it, price isn't TOO bad, but could be less.
Newegg.ca - COOLER MASTER Elite 330 RC-330-KKN1-GP Black SECC ATX Mid Tower Computer Case - Computer Cases Newegg.ca - BIOSTAR TA785GE 128M AM3/AM2+/AM2 AMD 785G Micro ATX AMD Motherboard - AMD Motherboards Newegg.ca - BFG Tech BFGEGTX260896OCE GeForce GTX 260 896MB 448-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Desktop Graphics / Video Cards Newegg.ca - Antec earthwatts EA500 500W Continuous Power ATX12V v2.0 SLI Certified CrossFire Ready 80 PLUS Certified Active PFC "compatible with Core i7" Power Supply - Power Supplies Newegg.ca - OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory Model OCZ2P10664GK - Desktop Memory Newegg.ca - AMD Phenom II X4 945 Deneb 3.0GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor - Processors - Desktops
basically same basic parts list, slight different case (previous model before the one from farther above, same basic case), different PSU, the OCZ from above is quite a bit more for some reason, this Antec should be more than sufficient to run the Video card and current system listed above.
price is more though, $673 instead, not factoring in shipping.
but options can be played around with for the video card, CPU to drop the price (Triple Core instead of Quad, Video card could be dropped to a Radeon 4850 instead, or Geforce GTS 250, etc etc)