It's a good price but the Barracuda line isn't intended for NAS use so it's unclear how reliable they are. But it's still tempting to roll the dice given how expensive drive prices are right now.
Don't take manufacturers' recommendations so literally. I've been running 6 WD Greens in raidz for 81000 hours with no issues. Home media library etc. At the end of the day, any CMR disk is basically the same as any other, excluding manufacturing defects.
I won that lottery with 3x 26TB Exos shipped. I decided to try and get two more but they ended up being HAMR (returned). Then I managed to find two more earlier manufacturing dates in store stock at a somewhat-far Best Buy that I was driving past anyway.
It felt like an unnecessary purchase at the time (I'm still waiting to CAD a CPU cooler mounting solution for the build in a new case that has room for the drives). But it seems like that deal is going to be the high water mark for a few years, at least.
I don't know- apparently for many years the helium levels stay at 99%, if we extrapolate they will probably last for a few decades. So my concern over helium might be a bit too much
That's a remarkably good price. If I had $1.5k handy I'd be sorely tempted (even tho it's Seagate).