I do not get why people is trying to decided the final cost of the console and the drive by matching the actual cost, 499 dollars / 549 euros. For me the bluray drive should cost 49 bucks. Really how much an ultra simple device like a disc reader should cost?
Without any context, sure it should be something cheap like $50, but look at it from Sony's perspective. Sony (like the other platform holders) don't really want us to have access to physical media.
What they really want is for the consoles to be digital-only so that:
1) all transactions (since they're digital and via the Playstation store) go through them
2) they won't have give anyone a "cut" of their first party title sales (ie retailers and the cost of burning to discs, packaging, shipping, etc.etc.etc.)
I can absolutely see Sony pricing the attachable drive at $100 because think about the two types of consumers involved:
A) you want a disc drive no matter so you'll pay whatever they charge (because they'll probably make it with some sort of proprietary connection so you have no choice)
B) you're not really that bothered about having a disc drive, and $100 is "phew a lot of money for a blu ray drive" so you opt to buy digital instead at least initially, and then sit on the decision of whether to get a disc drive later.
Sony wins either way.
Plus, imagine if they priced the redesigned console (without a drive) at $249 and then offered the disc drive for $149. That's $400 total, so still a saving over the current disc edition price, but you'd also get a bunch of people impulse buying it at $249. Even bigger killer is that it would essentially force Microsoft to discount the Series S (which is currently $299) or at least offer several months of Game Pass to sweeten the deal.
More realistically, I could imagine them saying $349 for the redesign and then $99 for the attachable disc drive. That gives them a total price of $449, which is still a price cut but leaves room to discount later on. I think the disc drive will stay at $99 though.
Assuming this is not a precursor to them completely taking away the ability to have a disc drive with the PS6, I think it's a good move all round because (I'm making some assumptions here) a lower "entry" price for PS5 increases the PS5 installed base even faster, which hopefully leads to developers/publishers dropping cross-gen sooner, which hopefully leads to more games really making use of the hardware, which hopefully leads to more people wanting a PS5, which hopefully....and so on and so forth.