I can't quote each statement easily from my phone so.
1. Sure, value is assigned differently depending on current location and market. Pretty much all of the trees are more than I am willing to pay because I wont pay that for any tree while supporting my family. Paying $600-800 for a relatively raw collected tree could be a great value for someone living far away from the rocky mountains though. Alternatively, I would have to fly, pay for lodging, materials and more shipping to get one of these home - probably at least $1500 to start. However, if you live in the rocky mountains maybe you could grab 5 of these Ponderosa Pines in a day's work. I think the entire collecting experience would be a value in itself but obviously not everyone can put in that time or effort.
2. Bjorns name will pull in more buyers and higher prices. However, I am not seeing the giant mark up on something that is clearly styled nursery stock material in development for a year or two like some others have done.
3. None of the maples in the sale are imports. They were either air layers or grown from seed by others and they have excellent nebari. Bjorn did not personally air layer or grow these but I'm sure he had a part in their development. I'm sure buyers can ask about specific trees if they want more details. I don't see any deception in posting full canopy trees without leaves as that is likely not feasible at this scale.
4. I have to agree that the quantity over quality is a big problem in the states. The appliances and building materials from our big box stores are abysmal. Bonsai prices are over priced in the US, especially online, and I hope this improves.
@Corwyn13 posted specific example of this recently that I agree are way over priced.
I'm glad that you shared some prices for context. Those prices are what I think bonsai or raw nursery stock should be. I havent seen many or any maples at our nursery that will have decent taper or nebari like you mentioned, but you are in a different country.