I see the bundle "202408 Warhammer Strategy Bundle" is available for $149.99. I have a coupon for 84% off, bringing it to $23.99. It includes:

202408 Warhammer Strategy Bundle contains:
Warhammer 40,000: Armageddon
Warhammer 40,000: Sanctus Reach
Warhammer 40,000: Battlesector
Warhammer 40,000: Gladius - Relics of War

Battlesector only goes 40-50% discount, all others 80-90% (according to gogdb.org), so this price is better than all 4 on their best discount by $9.97 ($33.96 getting best sale price of all 4 individually)

Would it be worth getting all 4 for $24? Or is one of them better than the rest and would get more out of just that one rather than playing all 4? Lots of DLCs, so it starts adding to the cost as you expand...

I currently own 3 of the 4.

Gladius is a ton of fun and kept me entertained for many hours. I even gifted it several times and have bought every DLC. Because there are so many factions available and they all play differently I'm still not bored of it.

However, I prefer Sanctus Reach now over Gladius. It's purely tactical and that's what I enjoy spending my time doing. The game still gets updates and a few mods have been made (you'll have to hunt a bit though, slitherine's website is probably the best place to start). I've spent way too many hours playing that one.

I picked up Armageddon simply because I was curious, but honestly beyond the first couple of games I tinkered with it, I haven't touched it since. I did find myself getting drawn into the gameplay though after I got past the visuals. I might go back to it, but Sanctus Reach ticks the same boxes and more so not sure I ever will.

I will likely pick up Battlesector at some point but after spending many many hours watching others play I can't see what it brings that Sanctus Reach doesn't already do, and less in some cases. Still, my curiosity will probably get the best of me. Maybe.