Crusader Kings 2 is currently on sale
https://store.steampowered.com/app/640140/Expansion__Crusader_Kings_II_Jade_Dragon/

IMO it's worth buying the bundle with all DLCs. On sale, the total price comes down to essentially a full-price game, but the DLCs are great.

"They might look the same, but they don't taste the same."