So, I buy printers errors... Here is how I estimate value for myself
In general the more extreme the more I'll pay but I have to like the card and players and the defect.   For me, backs are of no interest on errors of the kind, I only buy for fronts.  Miscuts I only care about if it's a star.   Bad registry / 3d effects I always look at, if it's bad enough I'll absolutely pay a premium, but to be honest the only time I'll pay a premium if it is a star player in a set I like with a really distinct issue.  For what it's worth.  That's for 60s and 70s .  Now t205s....

