Lets take a look at the Topping D30.... It has more inputs than your DAC and the same number of outputs.
it has a nice set of switches and its price is $100 delivered.
I have added the total cost of all the components inside (the ones that I could find the prices to) and found the prices were around ~$46 +/- $8.
That isn't including the cost of the case itself.
Assuming they can have the case machined for $10 (not too bad of a price since it is solid aluminum) that would leave a profit of $25-30.
That is shipping via Amazon though that will take 10-30% of the sale price, and the cost of delivery which would be around another $10.
Assuming that Topping is selling it for the MSRP of $120, its likely they are making less than $25 per unit when all is said and done.
On ebay there is one shipped for $105.
This is 10% ebay fee ($10.50), and shipping (atleast $10 from china).
That would leave the MFG with $79.50, of which they could have UPTO $66 of cost.
When it comes to a product like the DX7, from what I was able to source... the cost is closer to around $120. There are some unknown factors such as the screen (since I couldn't find it off the shelf) and the small SMD's that I can find part numbers to. I added ~$20 hoping to cover it all.
The case again could be made for maybe around $10-12.
Therefore the "profit" on this unit even at a cost around $150 would be much higher at the original retail price of $400.
But imagining $400 via ebay, thats still 10% ebay fee, 3% paypal fee. Which amounts to $42 + shipping from china ($20) which means around $62.
So that would leave them with $338, with a cost around $150.
The leaves them with $180 profit. Which is quite a nice profit assuming my prices are correct. But this is their "flagship" product.
They have all custom boards done themselves, custom firmware, and they have licensing with XMOS.
So all of this "profit" also has to pay for their R&D.
Nevermind that they are testing with an APTX555 just like what Amir has.
Unfortunately you have done NONE of this engineering, offer a product without ANY of the features or costs and yet your price is actually higher.
And yet you claim that I am another "clueless internet expert"?
The reality is that had you never shown up the Khadas tone board, when Amir disassembled the DAC we would have found it and searched it and this same backlash would have come.
There are plenty of other products that have been tested here with prices that are too high and performance that isn't too wonderful and as such have not been recommended.
As much as the benefit of the doubt has been given to you, your arrogance in this matter isn't helping your case.