yes, it will, but it will depend on who is buying them. For postal historians, it's likely to deflate the value; for FDC collectors, it's likely to increase the value; for stamp collectors, it's likely to have little impact, unless they like lightly cancelled stamps more than SON cancels
If i'm putting what you're describing up on the auction, i'd value it at the CV and indicate it's on a FDC and allow bidders to set its worth.
I have several 1st day releases (this batch: Hong Kong). Each contains a collection of stamps, making a set(four or more of the topic). I can find their Scott # and value but here's my question... mine are on official envelops, slightly cancelled. I would think the value in the book is for the individual stamps but does having them on a 1st day envelope make a difference to the value?
re: Free-range vs. First Day Covers
yes, it will, but it will depend on who is buying them. For postal historians, it's likely to deflate the value; for FDC collectors, it's likely to increase the value; for stamp collectors, it's likely to have little impact, unless they like lightly cancelled stamps more than SON cancels
If i'm putting what you're describing up on the auction, i'd value it at the CV and indicate it's on a FDC and allow bidders to set its worth.