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 to fundraise nothing or very little, 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 for families to fundraise the rest. We hope eventually to do so much fundraising that the families won't have to fundraise as much, 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.