Well, I'll say it, I'm all about getting great sound at a democratic prices, everybody should be able to afford good performance, I'm guilty of this myself, I do own and enjoy a topping product myself, but let's not kid ourself, this doesn't represent the real cost of things, And I'm not saying this in a diminutive way, how Asian manufacturer are able to achieve that, sorry but the maths just don't add up, and it's kudos to them really, it's an achievement. I don't know where you find those prices. A Pi is not 10 bucks, the Arduino board you showed me don't have a full WIFI PHY, just the chip. The mad volumes of consumer electronics, when you think mad volumes I mean smartphone level volumes, millions, got us to think that electronics are worth a dime a chip, but it's all an illusion. For example try to built a D10 like this as DIY, and you'll come about 3-4 times that just for parts, you didn't do assembly, marketing, distributors, retailers margin, etc etc etc. Great that Topping and a few others have enough of a solid mass around their bones to offer these ridiculous prices, but sorry, fitting a pi or an arduino and support only open source softwares to provide streaming capabilities, will never bring enough volume to warrant a sub 300$ price tag, no way on earth even China. Those modules are geared to appeal DIY, tech oriented geeks. But even then, built it yourself, and you'll break that 3 bills treshold, I guarantee this. To make volume, you'll need branding, and to have branding, you need pretty design, you need User friendly Interface, you need huge marketing, not put that on top of your cost. Again, if someone could offer that for 150$ He would. I challenge anybody to find a way to reach the price points you mention, good luck.
