Got a little extra money from work so I splurged and finally got the big Masks of Nyarlathotep hard cover boxed set. I was on my last couple days of an Amazon Prime trial account so I checked the price. It was just over $100, which I thought was odd since it had been in the $90s just a couple of weeks before. So I held off. Then once I got the email that my trial account had expired, I checked again. Sure enough, the price had dropped again, this time to $89.
I can't say for certain, but I have a strong suspicion that Amazon's pricing algorithm jacked up the price a bit based on my imminent Prime trial expiration on the assumption that I might be willing to buy some things to eke out the last benefits from my trial period. Then, when I didn't, the algorithm dropped prices again.
This now means I have three distinct versions of the campaign. Each has some strengths relative to the others.