We've looked around at many different facilities to do more in depth work by "professionals" because there's only so much you can teach your dog at home, and in the workplace. Nox is adept at the handicap doors and is still young, so is able to still learn quickly.
The important part for this phase is for you, as the handler, to do your homework.You don't want to send your companion, your service animal just anywhere. Online reviews can only get you so far. For example, we looked at over 17 places in our local area, and narrowed it down to 5 places after viewing online reviews. After talking with actual trainers and people who own service animals in the area, we learned that some of the places we had narrowed it down to, used negative reinforcement in training (pinch and shock collars), which I personally, do not think is proper or helpful.
Only reason we are now considering going to a professional for certain training tasks is because I felt more skilled hands were needed for retrieving items, mobility training, and honing his skills.
Taking baby steps from our Canine Good Citizen training, we decided to move to Off Leash training next, as well as the other requirements that are needed to be considered a service dog and pass the Public Access Test.
We we're recommended to go to What A Great Dog for Therapy Prep Classes ($100 for 4 sessions), or to simply see what the pricing would be to practice off leash training specifically (meaning no leash is needed for him to want to walk beside me.)
We also took a look into Karma Dog Training since you can go to them for just the Public Access Test (For $75) or Training including the test (for $1610)
Finally we also re-looked at Topaz Canine where they offer a "Owner Train" program (for $75 application fee + $5000 program fee) which requires a doctors note stating the reason you need the dog, the dog to have already passed basic obedience training (or the Canine Good Citizen Test), be available to go to 3 meetings a month, be financially available for the training, pass a background check, and pass a home check and needs assessment interview.
So as you can see, the cost can vary from where you go, and the more training you can do at home, you may be able to negotiate with them for a lower price.