The Salvation Army has very good programs, from 3 months to a year usually, and they don't cost anything.
I am Canadian so our provincial health care covers many different kids of rehabs, and often the rehabs will help the person find a sober-living place once the program is complete.
If I had needed to pay for all my son's rehabs and treatments, I could not have afforded it. And as an adult, he would not have been covered under my private health plan.
Salvation Army rehabs, AA and NA meetings, and some addiction counseling are all low cost or free options.
I find that the success of any program, or any method of recovery, is directly related to the addict's willingness to do what needs to be done to get clean. Many get clean with no program at all, just a determination to stop using drugs.