Briar Fox, Night Train, and Pirate Kake (and any other "Kakes") are considered "tinned" - not bulk- by Smokingpipes, even though they come as a shrink-wrapped brick. That's why the prices on those were higher last month; Smokingpipes's sale last month was only on bulk.
P&C's sale is on both bulk and tinned C&D tobacco, so if you loaded up on bulk last month, it is a great opportunity to grab some tins on the cheap.
You might take note that the pricing reflects the first 4 tins purchased on tins that offer quantity discount. If you look at the site, you'll see if you buy more than 4 tins, you might end up paying more per tin than you did if you would only have bought 4.
So it seems the 20% off doesn't scale to more than 4 tins per blend with qty discount pricing.