What would it cost to continuously print out every edit to Wikipedia?

In a recent What If…?, XKCD's Randall Munroe tackles the important question: "If you had a printed version of the whole of (say, the English) Wikipedia, how many printers would you need in order to keep up with the changes made to the live version?" Turns out the answer is SIX, but it would cost $500,000 a month for the ink, and you'd need 300m^3 a month to store the paper.

The English Wikipedia currently receives about 125,000 to 150,000 edits each day, or 90-100 per minute.[1]

We could try to define a way to measure the "word count" of the average edit, but that's hard bordering on impossible. Fortunately, we don't need to—we can just estimate that each change is going to require us to reprint a page somewhere. Many edits will actually change multiple pages—but many other edits are reverts, which would let us put back pages we've already printed.[2] One page per edit seems like a reasonable middle ground.

For a mix of photos, tables, and text typical of Wikipedia, a good inkjet printer might put out 15 pages per minute. That means you'd only need about six printers running at any given time to keep pace with the edits.

The paper would stack up quickly. Using Rob Matthews' book as a starting point, I did my own back-of-the-envelope estimate for the size of the current English Wikipedia. Based on the average length of featured articles vs. all articles, I came up with an estimate of 300 cubic meters for a printout of the whole thing.[3]

By comparison, if you were trying to keep up with the edits, you'd print out 300 cubic meters every month.

Updating a Printed Wikipedia