Massive response, TheNorman.
As you said, therapy can be a very powerful tool for recovery, but also for life as a whole. Problems will constantly resurface, so we would be best off having maintaining a solid army of strategies to help us deal with these 'barbarian incursions'. But as you said, there is a problem of cost. Where I live, these services -- which should be classified under Health, but are not -- are NOT covered by the national health care system. One has to be prepared to bleed a significant portion of one's income to make do with a bare minimum of one therapy session every two weeks for the next 6 months or so. Even so, in my limited experience of therapy, the help has mostly materialized along general lines: improving disposition, self-confidence and acquiring the wisdom that "my problems" are actually more common than I thought. Along specifics, like uprooting bad habits, it has not worked out for me. Disclaimer: I am not referring to EMDR, as this seems to be a more novel approach compared to the more traditional ones.
So question is: what to say to someone who is on the fence about therapy? Is therapy going to fix a problem like a mechanic is going to fix a car's combustion engine? Hardly... it would not be helpful to set someone up for high hopes only for disillusion to set in. But there is plenty of potential for therapy as way to become stronger as a person, more resilient, etc.. and again, all of that has to be measured against the cost. Not easy!! But if it were more accessible... then hands down, everyone would have the potential to learn from such an experience.