The same seller that had Blueprints for $17 has been dropping prices on a few games, causing Amazon to lower their prices as well. These prices are at or just below all-time lows for the item on Amazon with Prime.
These are the items I've noticed so far since I've been tracking them for a while and got price drop alerts but I started looking at these last night and the prices have continued to drop as recently as a few minutes ago. I'm not going to do the whole "prove that this is a deal" thing on this post - hopefully these are a catch for other Prime customers who aren't placing $100-150 dedicated game orders elsewhere. Sadly, I've placed myself on game-buying restriction so I didn't get any myself.