DLT IV tapes aren't that hard to come by if you want
to buy them, but if you don't want to fork over cash,
they're scarce. I'm hurting for them too. We use DLT
IV tapes at work, and when we needed more, we had to
buy them - we bought a pack of 20 refurbished tapes
for like $160 + shipping. Cheapest price we could find
anywhere.
-Ian