PTSD seems to be a big market for service dogs. However, every program I can find that helps people pay for PTSD service dogs is for military veterans only (If you know of one that isn't please let me know). Which is pretty sad considering far more people in the US have PTSD for non-combat related reasons.
If you can't get someone to help you pay for one, some of the trainers charge $20k or more. People hear stories about how service dogs can change a person's life completely and so when they can't afford one they buy a dog they can afford and attempt to train them on their own. There are lots of organizations and individuals out there providing information on how to do it. I'm not sure what the typical results are like, but I imagine its harder to accomplish than many assume.
My wife and I would have to save for years to get a $20k dog, so we've been thinking about trying to train one ourselves. It might be foolish, but when you're desperate you'll try anything. If they pass laws implementing fines for fake service dogs, I really hope they are thoughtful enough not to make it illegal to have a service dog that's not officially trained by someone that charges a fortune.