So I saw that the entirety of the expansion is going to be roughly the length of Chapter 2. What else am I missing that makes this worth the $60 (estimated) price when it is about a third of the length of (arguably short and lacking content) Diablo 3?
The Diablo 2 expansion only had 1 additional act as well and 2 classes, but it helped the games life time tremendously. Did you not read what else was in the expansion? New play style where you can just kill and farm, random challenging portals thru out the game. New loot system that gives you better loot, paragon levels are account bound, and the ability to change items affixes. To me this easily pays for the $60 that you put out for it. IMO its quite a deal to pay a total of $120 (If you bought both around release) to have a game that will be updated and has maintenance. Diablo 2 its 13 years old and they still do stuff with the game. Oh and the expansion came 12 years ago. So 12 years post expansion. To get that much attention for any other game you are more than likely paying a sub.
Locking this page, but before I do so, I would just like to point out that almost every single expansion Blizzard has ever done, has only been like $30, give or take the collectors edition.
https://www.deviantart.com/aerisot