Do you consider that it's 'better' than the one listed for £55? If not, I'd be temped to list it for around £50, and be the cheapest one around, and therefore have more chance of selling (and it doesn't 'owe' you much). I guess it's a case of how quickly you would like to sell it.
Also, although I don't know if this is true of books (I guess one of the other book sellers will be able to confirm this), generally with limited editions the lower numbers fetch more than the higher numbers, and you have quite a high number. I sold hundreds of limited edition model vehicles and the number 10 of 1000 would generally sell for over three times as much as say number 600 of 1000, strange, but true...
Anyhow, best of luck and I hope you sell it