[Police] Is the region 2, 2 CD / 2 DVD Certifiable box set really a rare collectable?!

Hi guys, Last Christmas I got two copies of the 2 CD/2 DVD box set, but hadn't got around to selling the spare one until now - it's still in its shrink-wrap. Checking online to see what other people were charging for it, I found that Amazon don't even stock it anymore (though some Marketplace sellers have it for £55!) - just the BluRay version and the 1 CD/1 DVD 'highlights' package. And on Ebay there are people selling it for £50 - 65, saying it's a rare item! Am I sitting on a 'Christmas bonus' here? Has anyone managed to sell the set for that kind of money, or are all those people on Amazon and Ebay just asking ridiculously high prices which no-one will actually pay? Angeline --