The electrical certification adds another cost for hardware. That is why wall warts and lumps are now ubiquitous. While Australia has adopted the IEC 230v standard, down from 240v, the supply voltage is often still at the upper end of the plus 10% permitted tolerance (max 253v). Where I am in metro Sydney supply at the outlet is typically 247v. So good idea for manufacturers to use power supplies that can handle up to the permitted 253v to avoid premature failure in our market.
Local distribution was mandatory pre-internet. Now manufacturers have the option of selling direct and negoitating a low cost international shipping deal with UPS, Fedex or similar. Cuts out unnecessary additional layers of intermediaries and their margin.
In reality local distribution of boutique product does not mean retailers will stock it. Using Audio Chocolate as an example you can find DSI product on display at some of the retailers they have listed, which in NSW includes only one with a decent KB section, but I have never seen a Numa on display at that shop.
I am certain that if you want to buy one the retailer would ask for payment up front, get it shipped from the distributor, assuming they have it in stock, and call you to pick it up when it arrives.
You could probably get it for less including shipping, and quicker, buying it from Sweetwater, no local warranty however. Of course you may be able to buy direct from Audio Chocolate but that cuts out their retailers which doesn't win them any friends amongst the retailers who prefer to stock stuff from a distributor who will not supply retail customers.
Software has eliminated the middle man, fast international shipping is now doing it for physical product.