Unless I'm missing something ... I looked at the specs and I could source modules and build this amp from parts for about $200 or I could build a better (freq resp, distortion, attenuators) amp for about $300 ... add in the labor and reasonable profit I guess what I'm saying is I don't see anything special about this HD amp for $750. Many options at this price point for better product. Also it's an headphone amp - why not say that in your product title to differentiate it from amplifiers that can drive speakers or amplifiers that can drive speakers and have an HD output as well?
JGaltThen go build the amp. There isn't a whole lot of point saying you could build something when you aren't. Also, in HiFi markup can be as high as 3000%. Why are you complaining about markup that is around 100% by your figures. If you don't think building the amp has a cost, or developing it have costs, or running a business have costs, than you probably shouldn't lead any corporation ever.