You're on the right path, but missing a lot of the key overhead costs in moving a consumer-electronics piece of hardware in volume. Your rough BOM estimate is

You're on the right path, but missing a lot of the key overhead costs in moving a consumer-electronics piece of hardware in volume. Your rough BOM estimate is close enough to accurate, but you'll also double that by the time you add in assembly, packaging, shipping (from Taiwan/China), and some sort of sales commissions (you're not going to just walk into Best Buy and drop these on the shelves). An online/direct-sales model can augment your big box outlet strategy, but is unlikely to scale nearly quickly enough unless the concept explodes virally. Or, you can do what you want from a price perspective and build a little niche business that supports you and 5 friends "nicely", but never becomes a household name.