I like this mindset; actually. The human psyche is so deep and complex. We're barely at the anatomy stage, let alone any sort of exact modeling or prediction.  

You're right - a Zoloft script is what, $30 a month even before insurance? A therapist can be $100s per hour.

I agree that a pill can't fix everything. Pharmacotherapy for anything is putting a chemical designed to modulate your body  and hoping that the tests we've done and the predictions we've extrapolated causes a successful outcome. And for many people, specifically in the realm of psychiatric disease, adjusting body chemistry is a cornerstone of therapy and can truly help. 

But it can't be the only leg of the stool. Cognitive and behavioral therapy are crucial build coping strategies and emotional strength. It's not easy - not in the least. 

If you'd ever like to collaborate on something about the cost/effectiveness of  different treatment modalities for psych disease,  or maybe about perceptions of ease of treatment of the above, let me know!