I may be completely wrong, but I get the impression that if I don't do owner-training than the trainer does all of the training and then hands the dog over to me, obviously with the tasks that are most appropriate for my symptoms.
Not necessarily, I'm technically owner training but I don't already have the skills myself, and this is my first dog. I've worked with multiple trainers, including the service dog trainer who we finally settled on. Elliot lives with me, he has since I got him five months ago, except for the two weeks he stayed with one of his trainers while I was away. We go to puppy classes (for socialization) one to two times a week. His trainer doesn't want to start doing individual service lessions until after he passed the CGC, which we're taking the first week of december. Then I'll have training every week with her. She's basically teaching me how to train him, and she's starting the behaviors, then we're working on them at home and going back to her every week to perfect things and troubleshoot. She'll also accompany me on public access training when we start that. My state does not give SDiTs public access rights, but she's well known as a service trainer and has a diverse list of businesses who welcome her, dogs she trains and their handlers.
As far as cost, I don't even want to try to figure it out. Maybe in a few years I'll go back and calculate the first year expenses. He was $1000 himself. Plus his bed, food, vet care, toys, leashes/collars/car harness, training (our classes have been between $40 and $60 an hour), gas to drive the 75 miles each way to training a few times a week, a crate, treats, nail clippers and bowls. There's got to be more I haven't listed. It's extremely expensive. My parents are helping me out a little, they paid for Elliot himself. They've probably paid for roughly a quarter or the remaining expenses.
I'm a college student too, Elliot lives in my university apartment with me as an ESA until he's trained enough to be an SD (so probably until I go to nursing school). If he washes out, I'll keep him as an ESA.
Another thing you have to consider is the wash-out rate. If your dog doesn't make it what will you do? Keep it as an ESA? It sounds like your horse is already an ESA for you, and you've said you need help out in public. Will you keep that dog and your horse AND get another dog? It's not fun to think about, but it's a reality.
At first I thought I'd rehome Elliot if he didn't make it, I have several friends who are fabulous pet owners and very committed to their animals who have said they'd take him at a moments notice. They own their own property and have yards, unlike me. After working with him for five months I've seen that he's an invaluable resource to me for my mental health and even as an ESA he has made a miraculous difference.