Agree - it’s the biggest problem I have with this model. I’ve often looked at various Paradox games (e.g., Stellaris), considered getting it, and then quietly dropped the idea again, because the total cost is way beyond what fun I’d get from the game at the time.
Though I think the problem is much less with the Warhammer games, because most of the DLC simply adds new factions. You can buy just the base game, and you’re still getting the “full” experience of the four base factions in the game - buying additional factions basically just gives you more ways to enjoy the game. In contrast, most Paradox games require 2-4 expansion packs in order to get anywhere near the game experience you should be getting. I understand that it’s hard to do it different for them, but it’s unfortunate.