Prices in USD (look up todays exchange rate, it's a good learing exercise for you) based on what I can get new equipment for in USA with rebates, sales, etc. and then discounted for being "used". After converting to Canadian dolars add 30-50% because you guys north of the border get screwed on PC pricing by the import duties.
$10 ATX case
$20 ECS K7S5A Pro motherboard
$30 AMD Athlon XP 2000+ CPU
$60 1GB (2x512MB) DDRAM memory
$5 1.44 floppy
$35 120GB hard drive 7200RPM, 8MB cache
$20 ATI Radeon 7200 video card
$35 LG 16x Dual Layer DVD-writer (brand new)
$35 (depends on size/version of PSU) ATX case, AOpen power supply
$40 (much less if RAMBUS memory) ASUS P4T533-C motherboard
$40 Intel Pentium 4 2.2 GHz CPU
$40 (only if someone who needs replacement RAM) 512MB Rambus memory
$30 (assuming 7200 RPM IDED) 80GB hard drive (new)
$30 ATI Radeon 8500 Dual head video card
$35 LG 16x Dual Layer DVD-writer (new)
$5 Linksys 10/100 network card
You may be able to do better selling it as a working system with Windows installed. Personally I can't give my old equipment away. Everybody sees the prices on a new Dell with a warantee and a free printer and laugh at me.