Gregory's Server
Malware authors and scammers have already been paying for Apple Developer accounts, and indeed putting their software in the crApp Store as well as distributing externally on the Mac. The price has never been a barrier, because crime does pay!
Price is only a barrier for some honest developers.
The very fact that Apple had to add notarization on top of the preexisting Developer ID certificates proves that the price of the certificates wasn’t a barrier for malware.
The negative side effect of the price is that it incentivizes honest developers and users to practice riskier behavior, i.e., releasing and using software that it totally unsigned.