I don’t see a problem. No one is forcing you to buy them and there are a lot of audio components that have or are going up in price. As far as the capacitor choice, the A3 are built to a price point, and the margin may not be there to put more expensive caps in them.
If you know so much about speaker design and caps, try building a pair and see how it works out for you.
If you know so much about speaker design and caps, try building a pair and see how it works out for you.