I really hate that almost every piece of TR merch is always only made for a very limited amount of time and then becomes pretty expensive in the aftermarket. I bought Volume 1 when it was released, but then I didn't have the money to buy the other books at release. Eventually when I had enough money to buy them, they were already sold out everywhere and only available for more than 100€. This is ridiculous! Who would produce comics in such a limited quantity, especially considering how beloved those are?
I'm also pretty sure that a lot of them got bought by those weird collectors who will never read them and just put them into storage unopened. Seriously screw those guys.