I know some people pay crazy money for rare/unusual things, but even that is extreme. The grading plays an important role of couse, SSS grade is the highest ranking I believe, the most white colouring, but I could be wrong - I'm not really up on CRS and grading. Its only worth what anyone is prepared to pay for it at the end of the day, I doubt it will sell.
Maybe it was a misclick and they meant £80.