The best part of capitalism and competition is that if the price is high, nobody will buy, it will have to go down. Personally I think the shop has done a great service for the hobby by promoting vintage audio equipment (they also have some nice new stuff as well).
Are the videos a little in your face, yep but that's the YouTube Way to get more views, they all have to do it now. The shop is putting in a lot of leg work to find, buy, fix and promote the equipment, if your equipment is less expensive, then you have a leg up and should be able to outsell them. Most retailers like to find that sweet spot of good profit margin and steady sales.
I do think some of his facts are off (and I might be wrong). Since Marantz has such a fascinating story and was creamed by global capitalism, it would have been more interesting to dive into the different facets. As far as I know, Philips bought distribution rights, and maybe some manufacturing (43%) around 1980 but Superscope and Marantz of Japan kept some products for their markets like the PMD Portables. I think Marantz of Japan made most of Philips Marantz Equipment but I'm not 100% sure. They did make a ton of equipment for the home market under Marantz and UNIX (by Marantz) Names during the 80's. The JDM Units seem heads and tails better then the Philips Component Lines.