How about marketing it as a kit? This would allow you to keep the cost down and you could market one as complete as well.
People like myself are adept at following directions and assembly, but I'm no engineer.
Some pots to adjust the startup and shut down timing would be nice.
Also, and this would make it just about perfect for in car use, how about some adjustable timed outputs for relays to control startup of items such as amplifiers? (to avoid the dreaded thump on windows start)
Maybe you could have a look at the Mp3car.com store and see if you could incorporate a brainstem like device (dsatx uses it) to allow user input on changing settings?
I'm just tossing out ideas here, I have no idea how to incorporate these (again, I'm not an engineer), but it seems you might have the knowledge.
Nice work all the same!
I really hope you find a way to market this affordably, it would solve alot of the problems I'm having to "band-aid" right now. I'm running a p4 2.26 Ghz and power is a bit of an issue right now. I'm using an inverter currently (not ideal) and a DSATX is pretty closed to maxed out for what I'm running.
Oh and about the apologies for your english, none needed. Your english is better than my (whatever your native tongue is, russian?) ever while be!