I'ld like to know more about the seller and preferably some reference from more long time users that you're a real and solid person before I order anything.
40 UKP (80$ ?) is a great price for an assembled unit, however I don't see any possibility that you can pull it off at that price. For how much do you think you'll get a spartan3 chip ? Add to that the 68k, PIC and ram. I think you'll need to double your prices for both the assembled and kit.
