Ah well. How disappointingly levelling ebay is when you're a collector of tat. I decided to auction off a few of my more amusingly esoteric things (a Captain Scarlet annual from the 60s and a foolishly rare 1953 Giles book)... I figured a hundred quid or so would come in handy.
A quick glance at ebay reassured me that the most valuable was worth a fiver at most. So I may was well continue to treasure them myself.