I've never bought damascus barstock or knife blanks, but Robtattoo helped me understand something important a while back-there's no such thing as "cheap" damascus. I would add to that, there's no such thing as GOOD cheap damascus. That being said, I've seen some really cheap damascus steel knives, which made me wonder right away about the quality. The more I understood what makers go through to come up with GOOD damascus, the more I understand why it should cost what it does. The skill and mastery of the process, along with proper selection of good steels that will weld well AND heat treat well is worth the price. It would really suck to buy some "so-so" damascus, get to grinding, then find bad welds or other flaws. Worse would be poorly chosen steels that you get to final shape and when quenched, BAD things happen due to non-complimentary steels....
I'd go with what Karl said-get it from a good source who's known for good damascus.
Jeremy