Barnabas

OP suggested using a fee to reduce trolling and somehow qualify users. It addresses the problem in a round-about way using economic incentives to filter "non-HN" users, or trolls. Inefficient.

In order to qualify site membership, why not require a non-monetary merit test? For example, one can only sign-up or comment/submit for a month if they can solve a simple computer problem appropriate to the site content, in this case maybe deciphering a simply double-encoded string (say, HTML entities + rot13 or base64 or something). If you only want only "hackers" on HN, make them "hack" their way in, like some kind of text CAPTCHA for computer geeks. I guess a math forum could make people solve an equation to comment, or a zoological forum could ask some taxonomy question or something.

If the real problem is that HN needs money for infrastructure in a depressed ad market, then call it what it is and do a voluntary fundraiser, ala Wikimedia or public radio. Those of us who value this site will pony up accordingly.

This could help a team of developers working on a project to collaborate on a design (real-time multiuser table editing maybe?) or keep track of revisions/branches to the data model. Think Writeboard for databases. Make a premium version that generates change scripts and sell it for $10/user/month. I wish I had done it first! Great job, Mr. Žára!