We do try. Our weekend Ed simply cannot be available all the time! Was it particularly bad?
"Tthrow-away" email addresses, as you refer to them, are blocked by our system as we're made aware of them. Users are unable to register with these hour-only-inbox services.
Prudie, to your original question: nice an idea as it is, I don't think it would work. People wouldn't pay, and, ultimately, it would kill the number of new users joining us. We want to grow, not shrink!
Spare Ed