RestitutorOrbis

Hello, could you please shed some light why a 50 pence coin from 1997 that looks the same to me (a total lay person in this filed) is listed at $6,000 and at $1? https://www.ebay.com/itm/Elizabeth-II-D-G-REG-F-D-1997-50p-Fifty-Pence-Coin-Rare/233668550728 https://www.ebay.com/itm/1997-GB-Queen-Elizabeth-II-50p-Fifty-Pence-Coin/164500835574 Is the first listing merely speculative? I don't see any obvious 'mistakes' in the coin to make it rare or unique, is there another determining factor in that? The second listing is of a rather worn coin but there are many others in better shape and still in the two digits. I happened to find such a coin on the sidewalk the other day and was very surprised to see them listed at such exorbitant prices. Is there something I am missing here? Thanks in advance for your replies.