I know it would be a lot of work, but most other companies that sell expansion packs or instruments have several short clips that demo the most popular sounds in the pack.  If I'm going to shell out $99 or so, I'd like to hear what I'm getting, since once it's paid for, the software is not returnable.  It's just a shot in the dark for the money.  I looked at the DSF site and they don't offer a chance to listen to anything, either.
Dang, if you gave me all of the packs, I'd make demo soundcloud clips that you could include in your promos, lol.  

The DSF site has a play button under the icon for every expansion pack to preview the sounds. For example, here is the Rapture page:

I did a video with sound examples for the Gibson Bass Collection, including the effect of the Rapture Pro instrument knobs.