So when companies buy cheap things from China, put their labels on them and sell x10-20 the price you do understand and buy that stuff without any problems. But exactly here you have an impaired understanding of capitalism?
To be honest, if you consider that a newly-released 4K movie costs 30 dollars, going on 70 (to say) for a premium one, is not that bad considering that you'll have an exclusive or at least WWA steelbook inside w/ goodies and s#it, and outside in most cases an exclusive artwork.
After that, you would have to consider that for every movie a premium ret. makes an edition, they have to pay fees/royalties to the movie's distribution house. And as someone who quite knows those type of things, I can assure you that's not all that cheap.
Also, I think that Scanavo would make you pay more for less steelbooks (so a premium), and something cheaper for a big print, like Warner. That makes sense.
So, after all, even if they are expensive, if they are VERY-WELL made, I could go for that, talkin' personally. At least for what I know, premium retailers earnings for an edition are not so impressive if you think every thing they have to pay in order to do those.
Of course I think also the average price is expensive due to premiums being exclusive, things for collectors, after all, and considering that they go all for a relatively small print.