Andrew,
Did you read over my parts list for the amplifier and base your shopping on that?
FYI, it cost me about exactly $300 in parts to build my first Gilmore with mini boards from ExpressPCB and I had to etch the power supply board myself.
Also, as the resistors, LEDs, and transistors should be matched near perfectly, many extras of these parts need to be bought which adds to the cost.
Then of course there is the time involved in creating the boards, drilling panels, not to mention shipping costs when you order from 5-6 different vendors.
If your parts list is that cheap, then I'd LOVE to know where you shop!
-antness