I just received my HFI 580s this past weekend, and I'm looking for the same thing! Interesting that we were both thinking this at nearly the same time. The cloth pouch just isn't gonna cut it when it comes to protecting my investment. This is my first pair of "nice" headphones, so a good case that is also not too expensive would really be ideal here.
the case measures 11.80" x 9.80" x 4.70" (exterior)
The only reason I actually got a case, not just a pelican, but any case is because I actively transport them with other gear and don't want to crush my headphones. The HFi line are built like tanks so if you don't have the fear of crushing your headphones with over 100lbs of other stuff, I'd just throw them in my bag and go. I'm drawing a blank on other cases that are in your price range and that aren't bulky. Sorry.
If you still want a case though, it seems that the Ultrasone one would be your best bet even though you don't like the price. It will provide good protection and won't be as bulky as the pelican.