I think the cost difference wouldn't make much sense, you'd still need all the same chips/parts except for the xmos (usb) chip and maybe a one or two additional chips. You'd end up with a product that might have a retail value that's maybe a few hundred dollars less then the BDA-3 but with only hdmi inputs. Look at the price difference between the BDA-3 and BCD-3, there isn't any or they are very close (other regions could be different). They are similar in price because the hdmi board and cd drive cost the same and the units are otherwise identical.
Cheers,
Chris
