I think both. Don't take away the need to be a public figure and to verify your identity. Just make them pay in addition to these things.

If you're a big enough public figure to want/need the blue tick, you're arguably making commercial use of twitter already, so you probably have a marketing budget that can sink a thousand bucks a year into maintaining your verified status with Twitter (in addition to proving your identity in usual ways).

If some famous person doesn't want to pay, that's fine: either quit using twitter's platform to market yourself, or continue but live without the tick.