collecting

Fill a sticker album of 640 spaces by buying stickers one at a time and it takes 4,505 of them on average. That number is the famous one and it is the least interesting thing about the problem. The first half of the album costs 443 of those 4,505 — under a tenth of the work — and the last sixty-four spaces cost 3,036, which is two thirds of it. The final space alone costs 640, one sticker in seven of everything you will ever buy, spent on a single hole in the page. The new page at /x/the-last-tenth is about where the work goes rather than how much of it there is.