laptop v desktop trade...opinions

I was offered this trade by someone on craigslist. It seems pretty legit.

I am giving up this:

Processor: Intel Core 2 Duo 6400 @ 2.13 GHz w/ scythe infinity cpu cooler
RAM: 2GB G.Skill DDR2
Video Card: nVidia GeForce 7600GTOC 256MB
Audio: SoundMAX HD Audio
Powersupply: OCZ GameXStream 700W
Hard drives: first - 250GB Seagate Barracuda SATA, second - 750GB Seagate Barracuda
Motherboard: Asus P5B Deluxe w/ built in WiFi
Case: Antec 900 gaming case
Drives: 1 - Lightscribe DVD/CD burner, 1 - DVD/RW-ROM drive
Display: Viewsonic X Series VX922 19" 2ms LCD
keyboard: Logitech Media Elite
mouse: Logitech G5 w/ some wear on the cord
for this and cash:

dell inspiron e1505 laptop
2 gb ram
160gb hd
1.66 ghz intel core duo
and I’m guessing the 4500HD from nvidia…
he is willing to trade his laptop for my desktop plus cash on his end. how much $$ should I ask along with his laptop?

Also - I will be using the laptop for photoshop and other multimedia. nothing extreme such as 3D rendering, or gaming. I’m guessing the only game I may on it is TF2. My setup is 4 years old, and I’m guessing his isn’t the newest either as it isn’t available on the DELL site anymore. I can do this trade, or I can hold on to my desktop and just buy a new laptop. Opinions?

+100?

thats what im thinking originally. i know i wont get much for my desktop straight up, so im thinking this is a decent deal. however, the desktop has the 19in and the extra space. and its really not that bad at all, still a pretty fast computer as whole.