Rereleases can definetely dull a games value. Xenoblade for wii and Radiant historia for DS used to be $60+ games, but rereleases and ports have dropped their values to like 35 and 15-20.
Are there not exceptions to this? I recall people saying the Saturn version of Radiant Silvergun was going to drop because of the re-release on XBLA back in the day but it still sells for quite high. Although, I haven’t checked recently so maybe it slightly dropped.