Yes, those prices are unrealistic, seems like the reporter didn’t make a good job at the math.
Those accounts go for way less, price depends on many variables, but you may be surprised how much of legacy payment system accounts are up for sale on the internet.
TLDR: It is cheaper to attack Stripe, PayPal, and others legacy payment systems than to attack the Model-based Detection built by Passport Team, because of centralized points of failure and similar risks associated with the Legacy Payment System.
If add additional friction to verify those payments then yes it could lower the risks, yet if the Red Team decides to attack the Rounds consistently then you may face two problems; the merchant reaching out to close the account or asking a higher fee because your transactions are labeled as “high-risk”.