That's atrociously low. I know it's caveat emptor when it comes to FOSS, particularly as the nominal price is usually $0, but that really needs to be bumped up for anyone that is publishing packages to a public registry.
I hope they both mandate it for NPM and publicly flog^Wflag any existing accounts as "2FA Not Enabled" so that users can use that information to make their own choices about which dependencies to include in their projects.