400-450 (Laptop or PC Build?)

i have a low budget of around $400-$450 , which is about the price of a Dell Inspiron 14
http://www.notebookreview.com/price/product.asp?product...

i was wondering should i build my own or just buy a laptop which include modem, webcam (Dell Inspiron include?), speaker

and i have a build from my friend
Intel Celeron E3200 (is this processoe good enough, or should i go for E5300 ar AMD?)
ASRock G31M-S
2GB Corsair Value Select DDR2-800 (1 x 2GB)
Sapphire HD4650 512MB GDRR2
Lite-On 24x SATA DVDRW
Western Digital 320GB SATA HDD
AcBel E2 Power 380W PSU
Normal ATX casing
BenQ G922HD 18.5" widescreen LCD monitor
Prolink keyboard and mouse combo
Speaker, Modem

other better build or AMD build is much welcome!!!