I have a Gretzky and a Lemieux in my traders since more than one year. Nobody ask for them. A lot have pop on eBay in the last months, some going for as low as 10 $. Both books for around 100 $, but I know I could NEVER get that much in return.
On the other hand, I look around for a Thibault (for the Nords collection) for more than a year. I never saw one priced at less than 12 $. I finally came around a mint one last week and get it for 5 $.
Over the last year, I manage to get all the Nordiques cards in Platinum (with three Forsberg et two Sakic, it have not been a walk in the park). So, in my experience, the market value of those cards seems to be very volatile. I know a guy who try to make the set and offer Beckett BV in return. Other than that, I have buy some way under the BV.
Hope it helps.