I suppose the relevance and value of these passes is dependent upon each collector’s taste. However, I do believe the example you provided is ridiculously priced. I added a 1971 NL pass to my collection for $75. As you can tell by my user ID the 1971 Pirates have a special meaning to me. I have considered having my 1971 NL pass slabbed. This would be first for me. I would likely have the slip state “Valid for 1971 Pirates NL Champions 97-65”.
I also have a 1971 Pirates season ticket holder pass for all of the games played at Three Rivers. Its rarity is purely speculative; however, it is the only one I have ever come across. It is in near mint condition as none of the games have been punched. So it can be safely said it was never used to see any game that season. Oddly enough for some collectors that distinction serves to make it more valuable.
I agree with your statement,
“From the sound of it, this pass may have never been used, but who knows. If that's correct, that is really strange and a little misleading for people looking for items from a certain game”. However, if you could find an unused ticket to Fisk’s first game it would cost you much more than a stub which was actually at the game. If given the choice would you pay more for an unused Fisk debut full ticket even though it had
“never been used”? If so you are collecting it for the rarity not necessarily the history. Even though I already own unused full 1971 Pirates opening day ticket I recently purchased an opening day stub because I couldn’t answer that question myself.
If you look at the picture I posted below you can see that these passes were looked upon as tickets, passes, and licenses by Major League baseball. Although my 1972 Pirates Three Rivers pass was used very often as evidenced by the number of punches surrounding it’s boarders, I have no way of truly knowing if it was there on Sept 30th. PSA has slabbed 4 of these as valid for Clemente’s 3000th hit. Conversely they have slabbed 14 stubs for that date. I understand the merit of the PSA population reports is questionable; however, it’s odd that there have been three times as many stubs slabbed in comparison to the passes. There is an online seller
http://www.chicagotix.com/Baseball.shtml who has advertised two stubs to that game and is asking $1,950 each or $3,795 for the pair. Ironically he also has a 1972 Pirates Three Rivers pass that he is asking $6500 for because it is in mint unused condition. I doubt he will ever sell any of these items at those prices but it does reflect his assessment of the value and rarity of an unused pass...go figure