I ordered my first box of VSL#3 DS about a month ago. Unlike VSL#3, the DS only comes 20 to a box rather than 30. I am a grad student, too, and unfortunately my school insurance would not cover it. The cheapest place I could have it filled was Costco, and it ended up costing ~$110 for the box of 20 sachets.
When I opened it up, I was rather surprised to see that DS looks to be two sachets of regular strength in one envelope. In doing the math, it seemed like ordering DS from the pharmacy would save pennies per dose relative to ordering single strengh from VSL and taking two sachets at a time.
Once I realized that, I saved the DS and have been using it to make yogurt in my Yogourmet (using the SCD procedure). My symptoms diminished significantly due to that yogurt alone (it was the only thing I varied), so for that reason I am greatly impressed with the product.