From an economical standpoint in relation to how much "fun time" you get out of it, I'd say no. Better to get mods and find a poor soul with good internet fiber who can by whatever dlcs there are (which at this point serve any viable purpose imho). I honestly don't recall any features in the previous dlcs that I have used to a serious extent except the lend lease before it was nerfed. Now the only thing it does is allowing people in MP to spy on their enemies tanks and planes and mix max tank/plane designs.
The base game is about 40, which despite its flaws has alongside with meme SPs and house rule mod MPs much more to offer than whatever a 15-20 dlc has. Bought the field marshall edition about 2 years ago, so I'll still get "more" out of it, but I wouldn't buy a DLC at this point, sorry, but that is what I genuinely feel. if PDX decided to actual bug fix and balance their dlcs better and focus more on game mechanics that make sense and are fun, then yeah, but right now, no. Even the upcoming dlc doesn't have a lot except some kind of features which help you attack forts and glide planes and air supply, but I don't think any of these are particularly useful more than the blitzarrow since microing is almost always better anyways except when you want the attack bonus. You can always just use house rules to deal with those issues though.