tough call. i would say a dollar but don't have any of the science needed to back up that claim. if it's more than a dollar, a lot of companies may stop using it and then it would get more expensive, not less- again, no science on that claim but i have a good hunch that it's correct.
at $.47 a mailing is much cheaper than a similar way to deliver data from point a to point b. no science on that but pretty sure it's directionally correct given my knowledge of data delivery systems.