there could be more errors of this type discovered and that would drag down the value
I'm not too sure that would be the case. If there were a thousand notes with such a dramatic error, those notes would still be incredibly rare since a 1000/10,000,000 or 1/10,000 is still .0001% of that series. This is still relatively rare so I doubt the book value would go down. The BV obviously depends on the condition, and the spectacular nature of an error (which this is).
What may deter people from buying the note above (and lower its market value) may in fact be that its a high denomination $50 which (in my experience) fewer error collectors collect/or desire. Its value is probably the same as if it were a $10 or $20 error.
However, its a spectacular error, so that general rule of thumb may also be thrown out the window. Error and anomalies are being collected by a new breed of collector, so as collecting goes, this realm is evolving, and the high denomination may have little bearing. Because high denomination errors seldom go to market their BV and market value is not as easy to determine. This may blow some sellers off this kind of note.
Errors seem relatively under-rated by Charlton. I think that's because, like specimens, they're collected mostly by pretty serious collectors. Its hard to say whether they track the trends of errors the same as they track replacements & other rarities. They only seem to be updating the categorization of errors at this time.
If I had an error note like that (or a partially printed $20 I saw earlier on this site) and wasn't a paper money collector, I would definitely sell it to a member here for 2 reasons. A) they would avoid the hassles with online auctions (deadbeat bidders, listing fees, and the obligatory credit card needed) and B) they'd get top dollar for it now while the market is hot.
Canadian Paper Money
