I was interested in the assertion that most books aren't fashion items, so it doesn't make sense for the price to go down over time. I'd have thought that this

I was interested in the assertion that most books aren't fashion items, so it doesn't make sense for the price to go down over time. I'd have thought that this effect would still be there, even if it's less pronounced than on blockbusters - publicity will be timed to coincide with the launch, and I'd imagine most people waiting for the next instalment will want it sooner rather than later.