You obviously compare players with other players in the position when you think about buying them. I'm not going to buy a player just because they're an Onyx, if I can get a Gold player who is better.
It's clear that 2K has changed the rates at which Onyxes are pulled and it's equally clear that individual Onyxes have different pull rates. Gasol seems to be very common and no one wants him, so his price is naturally going to plummet. When I got my Gasol, I listed him at 90,000 which was the cheapest at the time. Then 60,000 which was the cheapest at the time. Then 45,000 and he sold. I didn't want him and was willing to let him go at whatever the going price was, so long as I still turned a profit. Seems everyone else is the same.
People have indeed been going crazy with packs. I've also been getting bargains all day from people selling all the other items they've been getting in packs. Multiple Microwave, Posteriser, and Limitless Range badges for 500. Bought Durant for 40,000. Lebron for 50,000. But then I spend a lot of time on the market.
I get the apprehension, but it doesn't even make sense to dupe Gasol of all players, like another poster said if there's heaps of Dirks or Duncans on the market then that will be worrying.