Considerations...
I'll take what I can get, but I don't want to shoot anything corrosive
Back in WWII, there was never any .30Carbine loaded that was corrosive. That's why a surplus carbine will almost always have its original bbl, wheras one of the .30-'06 rearseneled weapons will likely have a replacement.
Ammo loaded nowadays, and not surplus, from overseas, will not be corrosive--AFAIK,
nobody loads corrosive primers any more.
Now, all of that said, my source of cheap, xlnt quality ammo for .30Carbine or any other cartridge I might fire, comes from Smokey Joe's Reload Shop. To paraphrase a T-shirt I saw at a beer festival, "Life's too short to shoot cheap quality ammo."
And I might get flamed for saying this, but IMHO, if your budget limits you to a $90 Mosin, that's one thing, but if you can afford a $500 M1Carbine, you can afford to buy, or make, good ammo for it.