so, officially, here's the current parts list.
from mini-box.com:
D945GCLF2 motherboard/cpu (89$)
molex splitter cable (allows for fans, hard drive, and dvd drive) (2$)
4-pin p4 cable (needed for this system board) (2$)
picoPSU-120 power kit (cord, transformer, and psu) (55$)
from newegg:
wd caviar blue 80g hard drive (40$)
dvd rom, since i don't need to burn discs on this machine (23$)
ddr2-gg7 pc5300 ram, one stick, 2 gb (30$)
including the 25$ for the box originally, that puts me at a total of 266 or so, assuming my math is right (148+93+25).
pretty awesome, all told. i might still get a video card, which would necessitate another psu, but that's just a possibility. a usb video card might be in the works too.