I think limited stock is one case. That was my experience. Saw the same limited stock at the Target by the office, stopped by on the way home and found two Ralphs, a Leo and a Mikey. I assume it's two per case of six figures, with the three figures each having their own TCIN, but don't know that for sure.
Grabbed Ralph and Leo. Left Mikey despite the sale. I'm not going to a completist with these and his lack of Ghidorah hands like in the artwork makes him pretty lame.
To be perfectly honest, I kinda felt bad about buying something so random considering the flood of preorders (and now a few sale items) that have landed on my porch recently.