They're 2.5cu.ft. bags if I remember correctly.Home Depot or Lowes should have the vermiculit/perlite in the garden center. The buckets you can find in the paint section.
Not in my area. It's either a huge bag or a tiny bag and I had to hunt all over town to find either.Garden supply centers sell bags of all sizes.
lowes does not have any i just looked and there small buckets are see through i'll check home depot and wally world today