"Playing with Crosby" is not the detriment you think it is. Anyone knowledgeable about Sid and Pens' history would know that it's actually rather difficult to play with Sid and have success. It takes a certain level of player to consistently work well and produce with him. While that may translate into high production what it also tells you is that Jake is capable of playing with star talents. He plays just as well with Malkin. Over the last 15 years, Pens fans have come to realize that not everyone can do it at the level Jake has sustained over the years.
So if you're the Avalanche wanting him with MacKinnon, or Vancouver with Pettersson, or Vegas with Eichel, or Edmonton with McDavid...there is absolutely a positive value to the "he plays well with Sid" part. If you are looking to nab him for the 2nd/3rd line with some random center, then fine whatever, but that's not where the market will be for him. Smart people know that. GMs know that.