Insulating a metal shop?

I've been shoppin all around since this thread popped up and it seems like the most affordable insulation is the good old fiberglass batt insulation.
I’ve been watching this one as well, and I’m about 90% certain I’m NOT going to spray foam the walls in my place next summer, but just go with fiberglass batts and call ‘er good. I can use the money saved on the spray foam elsewhere.