I would be suprised if you could get all of the parts for under $300 in low quantity. If you were manufacuring in the dozen(s) just the fascia, metalwork, screws and misc. hardware would probably blow almost all of your budget.

It would be cool to revive the empeg or a similar device, and I hope someone proves me wrong, but I would be amazed if you could get half the key parts for under $300 at low quantity.