All service dogs, no matter what organization they are from, take six to twelve months to train and thus cost approximately $33,000 to from start to finish. All the hours of training, all the food and medical bills and transportation costs, they usually add up to this same number (it just takes that long to individually and extensively train the dog).
Some large charities raise the full $33k themselves and then ask the families for nothing, and those charities are heavily funded organizations, often with multi-million dollar budgets.
Our smaller organization trains just two to three dogs per year, and while we do fundraise, we only fundraise part (up to half) of what it takes to raise and train a service dog, and thus ask the families for the rest. We hope eventually to do so much fundraising that the families won't have to contribute, but we are many years away from that goal.
 Coutts, Jason. "Cost of Canine Programs Across the United States." Syracuse, New York: American Society of Canine Trainers, 2012: 24.