One discounts to sell more than the competition
I don't think all retailers sell all they can sell, by a very long way. My local shop has had a K1 on the shelf for months. Another retailer claims to have sold 300 of them, but would not say if they are v1.3 firmware i.e. latest stock. Both sell at the same RRP.
But competition is bad for business. It erodes margins, cuts away funds for R&D, warranty support, etc. Hence we have price maintenance.
The internet has brought us a lot of discounting, which brought the danger of a near total loss of all retailers, because their overheads are bigger. And people would go into a shop to check something out and then they would buy it online
That still goes on all the time in the clothing business, where price maintenance has failed to work. So the manufacturers have moved to prevent this, by offering price support to physical retailers and by screwing the purely online ones.
But the consumer pays for all this...
What surprises me is how grey importers have been brought into line. One well known firm had to offer their own warranty. I bought a K100 from them, well below the then RRP. Now they are an official dealer.
It is possible the grey importers found business shrinking due to the lack of warranty on grey imports, but I doubt that.