[Arinoth]

Processor: Intel Core 220$
Motherboard: Infonec Computers - Computer parts Canada, PC Components, laptop computers, motherboards, processors, CPUs and much more : ASUS P8H67-I DELUXE R3 S.1155 INTEL H67, M.ITX, 1X PCIE X16, 2D.DDR3-1333/1066 (included wireless N and bluetooth) 140$
RAM: NCIX.com - Buy Mushkin Enhanced Silverline Stiletto 4GB 2X2GB PC3-10666 DDR3-1333 9-9-9-24 Dual Channel Memory Kit - Mushkin Enhanced - 996768 - in Canada 25$
Windows 7: Buy the Microsoft Windows 7 Home Premium 64BIT - OEM DVD at TigerDirect.ca 99$
Power Supply: NCIX.com - Buy XFX 450W Core Edition Single Rail ATX 12V 34A 24PIN ATX Power Supply 80PLUS Bronze - XFX - P1450SX2B9 - in Canada 30$ after 20$ MIR
DVDRW: NCIX.com - Buy LG Internal 22X SUPER-MULTI Drive Black Pata OEM - LG Electronics - GH22NP21 - in Canada 19$
Graphics Card:Gigabyte Radeon HD 6770 1GB GDDR5 PCI-E w/ DVI, HDMI, DisplayPort at Memory Express Computers 100$ (though probably could go with a cheaper one)
Case: NCIX.com - Buy Silverstone Milo ML03B Black mATX HTPC Case 1X5.25 2X3.5INT USB3 Supports 4 80MM Case Fan - Silverstone Technology - ML03B - in Canada 60$ (will hold your DVDRW + the Hard Drive) 60$
Hard Drive: Western Digital 1TB Caviar Blue7200rpm SATA III w/ 32MB Cache at Memory Express Computers 80$

This total comes into just under 800$ (excluding taxes). This would give you a very large wiggle room for increasing the performance for the price you want to spend, as well as up to 700$ towards the monitor.