Sony Vaio or Allenstein custom built computer

[primo99]

Whats up guys, need help with this one. I got this one guy who wants to sell me a sony Vaio for $600 its brand new not used here are the specs.
-Pentium 4 2.4 GHZ($999 buy itself at Best Buy)
-248 ms ram
-DVD
-CDR
And this comes with the flat 15' monitor($349)and
speakers but without a printer. All Brand new in the box(he gets a hook up so theres no warranty)the same one at best buy is going for $1300

Now my question is, should I buy this or get me a custom computer. I mean I want to get it for my DIGI 001 but also for general use, and the setup that I was going to get was the allenstein(yeah!!!)setup. the 2nd set up for $550 This is the price I got from United Micro which is all I can afford

assemble tests AND TESTED

Category Component

Cases Enermax Mid-Tower CS-3051L-B3A 350 Watt ATX Black
Motherboards Asus A7V600 VIA KT600 DDR400 ATA133 AUDIO LAN USB 2.0 ATX
CPU AMD Athlon XP 2500+ 1.83 GHz Barton Core 333FSB 512K OEM
Cooling Fans Thermaltake A4004D Copper base Heat Sink & Cooling Fan for AMD Atlon XP Duron
Memory PC3200 DDR400 512MB Infineon Lifetime warranty
Hard Drives Seagate ST380013AS 80GB 7200 RPM S-ATA

Seagate ST380013AS 80GB 7200 RPM S-ATA
Video Cards ATI RADEON 9200 128MB DDR 8X AGP DVI+CRT+TV
CDRW Lite-On CDRW 52X32X52 IDE INT BLACK
Warranty 1Years Labor,1Year Parts,Lifetime Tech Support (TS)
Total Price
$596.00 (is this a good price, and is this the correct setup)
Shipping Rates
$30 - FedEx Ground
$89 - FedEx Second Day
$129 - FedEx Next Day

You see this one is 1.8 ghz and the sony is 2.4 ghz and the sony comes with the monitor. I dont know how to choose... any input would be appreciated. thanx

Primo