The Collector Club numbers on Spyderco knives are entirely irrelevant to their value (ie., lower #'s are not worth more than higher #'s) and, as @kerole noted, some people (like me) dislike buying any knives with such numbers on them.
I do have a few Spyderco's with numbers on them but I bought them in spite (not because) they were numbered.
I once looked into joining the Collector's Club and, in addition to the general membership information, I was given a list of all of the numbers that were then available and was told that I could pick ANY number I wanted. I think the lowest number available then was #003 out of 200.
The main reason I chose NOT to join the Collector's Club was that you have commit to buying EVERY knife released w/in your membership category and you have to buy them thru an authorized dealer which means that I would have to pay full MAP pricing and could not get a 50% discount as an OpFocus member.
Didn't want to buy EVERY knife released and didn't want to forgo the OpFocus discount.
When you see some people dumping numbered knives on the Exchange after a new release, it's because they are Collector Club members and don't want the knives in question.
