Online purchases sold in lots of 10, 100 and 1000. Discounts for large orders. Filled bags (avg. 35-40 lbs each) are $3.50 each if you pick up; delivery is extra.
Lifespan is rated for 6 months of full-on sun/UV exposure, but that's at sea level. Bags can last shorter or longer depending on conditions. Their lifespan can be extended by keeping them out of direct sunlight, or by covering them with black plastic or dirt - or if you're using them for earthbag construction, with plaster or stucco.