Need a ballpark price for my M9700 Alienware Laptop

i am thinking of selling my alienware lappy, i bought it roughly 18 months ago.
Im confused when it comes how much i should price it for, it cost me a fair bit (close to $5,000 Australian). but i have no idea how much it is worth today.

i also sell it with the alienware carrycase and a spare battery.

I have sent it back to alienware for a complete clean up and check up so its completly ready to sell, all i need it your help.

All i need is an estimate on how much it is worth today.

HERE ARE ITS SPECS

AuroraT m9700

CPU - m9700 - AMD TurionT 64 Mobile ML44 2.4GHz 800MHz FSB 1MB L2 Cache
OS SYS - MCE - Microsoft® Windows® XP Professional with Service Pack 2
Case - m9700 - 17" WideUXGA 1920 x 1200 LCD with Clearview Technology - Saucer Silver
Motherboard - m9700 - Alienware® NVIDIA® Mobile SLi Chipset
RAM - m9700 - 2GB Dual Channel DDR SO-DIMM at 400MHz - 2 x 1024MB
HDD - Mobile - m9700 - Single Drive Configuration
80GB 5400 RPM HDD SATA
Optical - m9700 - 8X Dual Layer DVD+/-RW / 24X CD-RW Combo w/Software
Video - m9700 - Dual 512MB NVidia® GeForceT Go 7900 GS - SLI Enabled
Soundcard - m9700 - High-Definition Audio with surround sound
Wireless - m9700 - Internal Wireless 802.11b/g miniPCI Card
Ethernet - m9700 - Integrated 10/1000Mb Gigabit Ethernet & 56K V.92 Modem
Bluetooth - Integrated Bluetooth® Device
alienware messanger carry case and spare battery