Just received my December Issue of Game Informer Magazine (Owned By Game Stop) in the mail today and on page 17 they are advertising their Exclusive Black Series 6-Inch Purge Stormtrooper. It shows it available at GameStop.com for $19.99.
I believe GameStop.com is trying to push the Jedi: Fallen Order and Figure Game Bundles until a certain date then will offer the figure on its own, which should not be too much longer.
Game Stop Stores have also been selling this figure from canceled Game Bundle Preorders and some extra stock for $22.99. They should receive more stock very soon as well since they are advertising it in their 2019 Holiday Gift Guide (Page 32) and Game Stop TV in store ads.