Thanks for coming back to me. And i agree; no right or wrong

I guess time will tell with recent releases, but I'm not sure if applying a blanket percentage or amount (aside ofcourse from saying something like "you lose a grand or something upon unboxing") is the best way to go about pricing (say if somone asks in the "how.much is this worth", as there are so many factors and yiu are spot on when you mention something like Godzilla, where something many went out and bought NIB. Brilliant game and even though a fair few have sold on here; when they do come up, people (from what I've observed) snap them up quick.
I do thing JJP g'n'r isn't a great example on price reduction though, as generally speaking, it's not a very highly regarded game (I overpaid maybe for the one i had; amazing light show, but gameplay wasn't enough for me in a 1 game collection)
Even when there are recent sold prices to compare to, it doesn't necessarily mean that's what the latest seller is going to let their game go for (or likewise, just because person A paid £X that month for let's say a Tron LE , it doesn't mean person B will be willing to pay that much) .
If a particular game holds a special place in someone's heart for one person, they are more likely to be up for paying more (especially if only one of that game for sale) or will value decent mods or upgrades, compared to others with say huge collections who are less precious about it all , prepared to wait, and o.k to just take a punt (if the price is a steal/desperate seller) on a game before trading with one of their pinball buddies or whatever.
I know I've probably just rambled on there and stated the obvious..... sorry!