This is a very sought-after title, especially up to about 1974/1975. You just don't see them advertised that often.
A 1969 in VG but with dark edges sold on eBay UK for £21 Aug 2008. Going back through some old catalogues recently I see a first Buster book achieved an incredible £238 in a Vault Auction Mar 2006. Clearly some auction fever going on! Mid to late 1970s Buster books are also not that common so worth picking up if you see them.
Note: some PR issues may have no value. Selected issues in FN, VF or VF/NM may not exist in some titles.