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).