I think it was an article in Photo District News, and the justification for it was that if you were buying art that was also investment grade, then editions of more than ten were just not limited enough. It's rather specious logic, but that was what they were saying. I don't know why ten is just so much more limited than fifteen, or twenty, and how it became THE magic number, but that was the report in the article.
Originally Posted by Alex Hawley
The whole idea of the limited edition is that you DON'T print more, once the edition is done. If you sell the entire edition, and didn't make enough money, then raise your prices next series.
The driving force behind destroying the negative in some way (or at least rendering it unprintable with a hole-punch or scratching an X through it or something) is to make buyers feel comfortable that you're not making more prints of it, so they're willing to pay more to buy the print, because they KNOW that once #10 or whatever is sold, there will truly be NO MORE COPIES made. It's just another trick to "add value".