This means that the top 100 contributors (https://news.ycombinator.com/leaders) plus PG (https://news.ycombinator.com/user?id=pg) account for only about 10% of the total karma (3222034 points as of the moment). I expected their part to be greater. I should say "sorry" to the average HN user for underestimating his impact. :-)
Right and there's about 9 million items, so average is 4 points per item. I don't feel the average is very meaningful in this case. I'd also want to know, range, median and mode and a frequency histogram for the 100 largest, 100 frequent, and 100 rarest item scores.
Karma isn't worth anything directly but on HN it is a fair proxy for comment quality -- and quality HN comments have a monetary impact.
For one thing, quality comments take time and effort to write. Suppose a comment takes 5 minutes per to write per karma point earned. Then 32553783 karma points are worth 32553783*5/60/24/30 ≈ 3767.8 man-months or approximately 314 man-years not spent doing something else.
This isn't to say that HN comments just lose the authors (or their employers) money due to opportunity cost. I would not be surprised if for a number of HN users their commenting led to new clients and business partners, not to mention exposure for their open source projects or simply memorable discussions the impact of which is harder to estimate in monetary terms. (For example, the recurrent discussions about Stoicism have made converts.)
Then some comments may not make the author money -- at least not as directly as getting a new client -- but may be worth a lot in terms of the money they make others; patio11's long comment history comes to mind.