It lowers the value to me.
I have but don't like to buy any knives with numbers or other "special" markings on them beyond the brand's logo, place of mfg and blade steel ID info, which is how Spyderco normally marks its blades.
So, given a choice between a blade w/a # on it and not, I'll buy the one without the # on it.
------------------------------------------------
BTW, I looked into joining the Collector's Club at one time and discovered that you could pick any # available at the time you sign up. As I recall, I could have picked a # as low as #5 and as high as #190 something.
So, the # on the knife is entirely irrelevant to its value; ie., a lower # isn't worth more and a higher # isn't worth less!
The reason I decided to NOT join was because you had to buy EVERY newly released knife (within the membership category that you selected) whether you wanted it or not (which is why you see newly released knives w/#'s on them flipped after a new release) and because you had to buy them (at MSRP) thru a Spyderco dealer. As an OpFocus member, that would have made no sense $ wise.
This is a link to an old post regarding the Collector Club "rules" then in effect:
Spyderco Collector Club Rules circa 2009
Not sure if these rules still apply or if the Collector Club still exists. When I inquired about the Club around 3 years ago, I was told they were planning to make changes to the Club but I do not know if they ever did or not.