how much is my computer worth?

here is all the info about my emachines. T5048 (2006)
CPU: Intel® Pentium® 4 Processor 524 with HT Technology
(3.06GHz, 533MHz FSB, 1MB L2 cache)
Operating System: Genuine Microsoft® Windows® XP Media Center Edition 2005

Chipset: ATI Radeon™ Xpress 200
Memory: 512MB DDR (1 × 512MB), 400MHz (PC3200)
Expandable to 2GB
Hard Drive: 160GB (7200rpm, 2MB cache)
Optical Drives: 16x multiformat dual-layer DVD±RW
(Up to 8.5GB with dual-layer media)
Write max: 16x DVD±R, 6x DVD-RW, 8x DVD+RW, 4x DVD+R DL, 40x CD-R, 24x CD-RW
Read max: 16x DVD-ROM, 40x CD-ROM
Media Reader: 9-in-1 Digital Media Manager™ (Memory Stick®, Memory Stick Pro®, MultiMediaCard™, Secure Digital™, CompactFlash®, MicroDrive, SmartMedia, xD-Picture Card™, USB 2.0)
Video: ATI Radeon™ Xpress 200 integrated graphics
Up to 128MB of shared video memory
PCI-Express® (PCI-E x16) slot available
Sound: 6-channel (5.1) high-definition audio
Network: 10/100Mbps integrated Ethernet LAN (RJ-45 port)
Modem: 56K ITU V.92-ready fax/modem (RJ-11 port)
Peripherals: Standard multifunction keyboard, 2-button wheel mouse, amplified stereo speakers (USB powered)
Ports/Other: 5 USB 2.0 (1 in front, 4 in back), VGA external connector, parallel port, serial port, 2 PS/2 ports (keyboard and mouse), 5 audio ports (2 in front, 3 in back)
Dimensions: 14.25″H x 7.25″W x 16″D
Weight: 22.5 lbs
Software: Microsoft Works® 8.5, Microsoft Encarta® Online, Microsoft Office 2003 Student and Teacher Edition trial, Microsoft Money 2006, Adobe® Reader 7, CyberLink® DVD Solution Suite (PowerDVD™, and Power2Go™), Microsoft* Windows® Media Player 10, Microsoft Digital Image Starter Edition (60-day complimentary trial), RealNetworks RealPlayer®, QuickTime, Napster 3.0 (30-day trial), Microsoft Internet Explorer, AOL® 9.0 (6-month membership included ), Google Toolbar™, McAfee® Internet Security Suite™ (90-day complimentary trial), BigFix (identifies and resolves problems that affect the system before they occur), eMachines® Games Powered by Wild Tangent® (pre-installed with 10 demo games with 60-minutes of game play), Windows Vista® Capable