In Washington voting is free. My ballot comes in the mail, I fill it out, I drop it in the outgoing mail. It's pre-stamped. I don't mind full citizenship verification at the time of registration, as that can be done months before it's actually time to vote.
A (small) majority of states require employers to grant time off to vote and a (large) minority require that time to be paid. Although as others have noted, it is often the case that the window for voting exceeds a single shift (dependent on your area of work).