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Why the hell is Victoria 3 DLC so expensive
(hexbear.net)
Tabletop, DnD, board games, and minecraft. Also Animal Crossing.
3rd International Volunteer Brigade (Hexbear gaming discord)
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I think they're obligation DLCs made at low cost to fulfill the deluxe edition promise of "3 free DLCs" or whatever. They did the same with CK3.
From a production standpoint it probably makes sense to have some smaller DLCs just after release because most of the team needs to work on patching large release issues.
As for the price, it's just greed.