Steemit already offers paid memberships, though. I paid slightly over 2 mBTC for this profile and 4.5 mBTC for a secondary one. (The system failed to create the secondary profile, though).

You say:

Paid subscribers will be able to (...) become a verified user

The advantage of having a paid account is that one doesn't have to be verified, and have their account created automatically (unless the system fails, and doesnt't create it despite receiving a payment). What's the point in introducing verification to paid accounts as well?