It pushes the scalpers out of the game, which means there's less idle inventory, and the price can come down a little faster.
Another alternative is to sell at MSRP, but bind it to the buyer for a year. This means that it can be only be resold as a brick within a year, which is obviously unattractive to scalpers. To prevent scalpers selling a sale-sniping service, just take orders from qualified buyers anytime, then fill them randomly in e.g. a 7 day window. Within a week you either get a PS5 bound to you or a refund and a chance to try again.
I like your idea about the fluidity of market rate with something being done good with the amount above x price
And those are usually not much of a surprise in price generation over generation without something being radically new
Defeating the scale part of the scalper attack means charging an entrance fee, or using some other "proof" that hard to get at scale (like a credit card number). I like the idea of a long-term refundable reservation fee (pay $25 to get on the lottery list via distinct credit card, and if it's not delivered in a year or two you get your money back).
Something like a Gamestop membership is somewhat useful as well, but I'd just really rather see the manufacturers adopt reservation systems.
Of course this is all just idle speculation. Lots of smart people (on both sides) have been thinking about this problem for a long time.
As a sibling comment bored, there are ways to deal with this, but honestly other than selling them at market price or somehow making more, most options are limited, because that's just how the market works.
I'm not going to begrudge someone making a couple hundred extra bucks because they got lucky. That money isn't coming from you or me, it's coming from Sony, who could be selling at that price but isn't because they want to manage customer expectations. PS5s cost the market price, and Sony happens to sell some at a steep discount, and some people make some money out of that. If Sony didn't sell at that discount, you'd still have to pay the same amount, but Sony would be getting the money, because the market demand and current supply is such that PS5s cost a lot of money.