Ancient Atms, out of India, has the lowest prices for damascus
billets and blade blanks. As to quality, you’ll need to do cutting
tests yourself. Happily the stock is inexpensive enough that you can
waste a bit without feeling much of a pinch.
FYI, the Turkish and Persian swords that came to be know as
"Damascus steel" in the West were made in India. They’re called
Damascus for the same reasons that the beautiful straw hats woven in
Ecuador are called Panama.