This can work with an ad profit-sharing model for people who post content (which is how sites like ustream work, as far as I know), but that model doesn't really extend to article aggregators and I highly doubt a user would donate $1 to the community every time he sees an article he likes. An entire newspaper doesn't cost much more than that (nor do I think any balance of cost-to-post vs cost-to-upvote would really work). And you don't want users with deep/generous pockets doing all of the upvoting while the rest of the community is leeching.

If you could manage to build a reddit-style community behind a pay-wall, the pay-wall could be used to generate the 'finder's fee' money for posts and you could allot every customer x number of 'coins' that they could upvote with--needs to be tied to what they pay to prevent scamming. The end product would need to be vastly superior to HN to have a hope at attracting the initial community, but that's basically what Bloomberg machines do for finance, right? I'd easily pay $100/mo if not more for the best hacker news and commentary on the web (you could have the same pay-to-post, get-paid-for-upvotes model for comments to keep them quality).

So it's a $1 advertising fee? Are I guaranteed that the posting will appear? Do I get a refund if it isn't, and if not, what does HN do if I take the issue to the credit card company? Do I get a discount for many posts? Will HN take foreign credit cards? How does HN pay foreign people? Is there sales tax or any other tax to worry about? How does the infrastructure change to handle credit card processing?

That's all above the question of 'how much will it improve the site?' and 'will it prevent people from giving good, interesting links?'

There's what, a few hundred new links per day in 'newest'? That's ~$200 minus credit card fees. Is that enough to manage the headache of dealing with the issues surrounding money?

My answer to these is "no." It's not worthwhile. What are the problems you're trying to solve?

Then people would double check their spelling before committing a post ;)

You would lose all the casual members like me who occasionally have useful things to say -- even more so on Reddit. You thought the Digg redesign was a bad business decision? Implement something like that on Reddit and most of their userbase will vanish overnight.

Then there would be a lot more different crowd on HN, more people trying to monetize on their posts.

This would get in the way of innovation.

It would be the end of the essence of HN.