If you search for "Corrections" in Nature Publishing Group's journals, you see that many / most are labelled as "free" and in fact, they do seem to be free. That is until about 5 years ago. As far as I can tell, most "Corrections" published prior to September 2007 are not freely available.
For example see this correction where we are told
"In the News & Views article “Chemical biology: Ions illuminated” by Christopher J. Chang (Nature 448, 654–655; 2007) an error crept into part a of the accompanying figure."Tantalizing. To find out more you need just pay $18.
Or in this correction:
"In the News & Views article “Organic chemistry:A tuxedo for iodine atoms” by Phil S. Baran and Thomas J.".Not so tantalizing. But nevertheless the full correction can be yours for just $18.
Or this one:
The story ”That's no laser, it's a particle accelerator” (Nature 443, 256; 2006) incorrectly stated that the device described could accelerate electrons to 0.15% of their initial speed.This is one of my favorites:
"A misleading statement appeared in the News and Views article “Cardiology: Solace for the broken-hearted?” by Christine L."Want to know what was misleading? $18.
How about this one:
In Karim Nader's News and Views article “Neuroscience: Re-recording human memories” (Nature 425, 571–572; 2003) the citation of reference 6 was unclear. The reference concerned — Siegel, J.
How about this one:
"On page 875 of this Article, there are some typographical errors in the equations used in the computer model. The errors are in the third and fourth full paragraphs on this page."Some don't even have any clues. For example in this one we just know the problem is in an article on Transatlantic robot-assisted telesurgery. Or in this one the issue is with ancient homes for hard-up hermit crabs.
I could go on and on and on.
The corrections one needs to pay to see go back to the 1800s. For example in 1893 J. J. Walker wrote:
"The next two paragraphs will require slight modifications accordingly; and the last will, of course, be unnecessary. I owe this correction to a correspondence with which Prof. W.". Alas, we can't know the rest without - wait for it - without paying $32.I think we should have a context. Find the correction for which the free part is the most absurd or tantalizing. I don't know if other closed access journals do the same thing but it would be great to know ...
UPDATE: Some more fun stuff from Nature. There is a paper from Nature in 2005 "Making sure corrections don't vanish online". It is, of course, available for just $18.