I would buy it if I needed one.

The DA G4 has agp 4x and a 133mhx bus vs AGP 2x and 100mhz bus on older G4's so its a more capable and upgradable machine.  Almost all good AGP vid cards now need 4x minimum.
Mac mini C2D 1.83GHz - 2GB RAM - 200GB 7200rpm HD
Sawtooth w/G4 1GHz - 1GB RAM - SIIG SATA w/2x1TB HD
B&W w/G4 600MHz - 1GB RAM - 2x80GB HD
Sawtooth G4 400MHz - 512MB RAM - 40GB HD
Dell Ultrasharp 2007WFP 20" Widescreen LCD
2.94TB Total Storage