Charging money does not seem a very good idea in a site like this where you expect users to upload all the content. Also this would require credit card info which is a massive barrier, even if you were to charge just 1 cent.
I once proposed a scheme like this where you would donate to charities who would post lists of serial numbers they had received, for this purpose, but it never got anywhere. Maybe we need it more now than we did then.
I guess instead of mailing a $1 bill, if necessary it could be a hand drawn picture of a kitten (artistry not required). Authentication would involve checking the paper for pressure marks made by the pen. I wonder how many would take the trouble to fake that.
It feels wrong at first to pay for commenting on a forum, but the alternative is almost always a gentle slide towards a trash dump. AI means that slide is almost a vertical slope.