I don't know. I really don't have a sense of how much I value my witness vote even in the current environment, and it would obviously change a lot if everyone were selling votes.
I think in the most likely scenario I'd sell some of them and give some of them away. But like you I don't use all of mine now, so the question between getting something concrete for them or just the satisfaction of not voting for some people would probably tilt toward the money.