I can't think of a very many high end collectibles ever that didn't follow this pattern. Regardless of what the long term secondary market price does, the overwhelming majority of $100+ items spend some time in a price "dip" a while after they ship. It is an extremely rare case (usually implying an ES that was dramatically too low) when something doesn't at least briefly get clearanced.
If you want to optimize for spending the absolute least on this hobby, you'd be well served by never buying *anything* until it actually ships to retailers. On a rare, rare occasion, you might end up having to pay more than MSRP for an item that way, but you'll more than have made up for it on all the other stuff you got at deep discount.