I saw that the BECNT is offered in the Back-to-School Sale.
Since I have all volumes but one, I thought I would be able to get the remaining volume on Galatians with a discount. Turns out that buying the volume separately would cost me $44,99, but as part of the whole series, the same volume will cost $49,99.


Of course, I could still save 3 dollar or so on this volume by buying the series during this sale, but it's not even close to the 31% discount that for a minute I thought I would be able to get.
Does anyone understand why buying one volume separately is cheaper than buying the same volume in the complete series with dynamic pricing?