It takes between 13 to 123 heads (or 830 to 3,375 kernels) of barley to produce a 12 ounce bottle of beer.
Dried malt extract offers more fermentable extract by weight, meaning you need less of it to achieve a target gravity. DME tends to keep longer with fewer storage issues. It isn't known for getting darker over time, as sometimes happens with liquid malt extract that has been stored for too long.