Welcome to the forums, I would definitely suggest starting here with this thread. The origin date on this is back in 2015 and its been revived and updated with new things a good amount over the past few years.
To your point on when or if they will have a price jump, they are still selling in mint sets, I fear the price will never change. Its an anomaly that should never have happened, and that large amount of cards should never have hit the secondary market in pristine condition. At the best I would say only 10% of that large stock should have ever hit the secondary market in my opinion. The rest would have been normally handled and never been given a high PSA rating.
www.elitefourum.com/t/mystery-of-the-entei-suicune-and-raikou-goldstars/13863/1