Good price compared to what I've been seeing.
, I've been strictly looking for 9 mm on ammoseek, nothing under .60 cents.
If I had a choice , is brass superior to steel casings ?
Yes, but not as much as some would have you believe.
Brass will usually be higher quality ammo, but not always. Brass also expands to seal chambers and not allow blow by. Brass also is almost exclusively boxer primed and more easily reloaded.
Steel is non expandable in the shot process. It is very mild and in reality not much harder than brass on extractors and ejectors. People say it is "dirty" and it kinda is, but not so much from the powder as the blow by because of lack of expansion noted above.
It works, it is cheap(er), it may be more easily found, and if you clean your guns, will do you just fine.
I have rifles that have lived on a steady diet of steel ammo and have not seen any "worse for the wear" in them. Hornady used to make a steel cased match for 5.56 and it was a gem.
I don't do hundreds of round ammo dumps, or shoot auto so I can't help with the "Studies" that some companies have put out. Just my use.