It comes down to supply and demand. NIKE will NEVER release the MAG as a consumer product. In 2011, they made and sold 1500 pair and got as much as they could with an auction which raised just under $5M (that was later matched by eBAY). In 2016, they made a power laced version and sold just 89 pair via a lottery. I do think the lottery was more fair as it gave more people a chance to own these shoes.
My point being, you will NEVER walk into FOOTLOCKER or some high end sports shoe shop and see these on a shelf.
So as fans of the film and this shoe, we have NO CHOICE but to buy replicas out of China. After the games in 2008, the Chinese learned something that radically changed their way doing business with the west - make smaller runs of a better quality product and the west will pay more for them.
This is WHY we are paying $499 for a replica of the NIKE MAG. Do we want to pay that? Of course not. If we could get these for $200, those of use that bought these should would have bought 2 and 3 pair. When I visited China in 2010, I was shocked to see the prices of items in shops were the same as what we pay in our shops. At the time of my visit, 2500 Yuan (RMB) was about $480 Australian. An item costing $60 in Australia was 280Yuan. After dollar conversion, it was not much cheaper to buy in retail there.
The prices we pay online would be the same as retail there, except as I mentioned. you won't find these in any shop.