Whether high quality products always requires high total cost?

In the long run, the answer will have to be yes.

Think of it this way: If you can make something that is higher quality for a lower cost, then the competitiors who make a lower quality product at a higher price will go out of business. In the long run, the higher quality will win. If the competitor makes a lower quality product at a lower cost, the competitor can stay in business only by charging a lower price, and they can do so only because the costs are lower. In this case, the higher quality requires a higher cost.