I would like to have my left ear pinned back to be as symmetrical as my right ear.

A one-sided otoplasty can accomplish pinning just one ear back which could make the ears more symmetrical. This  procedure can be performed under local anesthesia. For many examples and our current price list, please see the link and the video below

Without photos it is impossible to say if it can be done and how much it might cost. Ear deformities come in a wide range of complexity and some are even multistage surgeries. The simplest can be done under local anesthesia. Because of this, the cost will also vary widely.For a straightforward common mild/moderate prominent ear on ONLY one side under local anesthesia, the total cost in my office would be in the $2000 - $2500 range.

Ear pinning, or Otoplasty, is a quick procedure that attempts to make both ears symmetrical. These procedures require excellent awareness of the anatomy, technique, and limitations of the cartilage. 
I usually do these procedures awake for several reasons. 
1. it's very easy and painfree to numb the ears
2. I can compare both ears and take measurements easier when the patient is awake (when asleep the surgical ear is up and the other one is in the bed)
3. My patients are able to fine tweak and give feedback during the case- we don't stop the case until your happy. 
Doing the procedure in the office is also much cheaper than anesthesia and surgery center fees etc.  Perhaps you can find a surgeon to perform these in the office. 
Hope this helps and God Bless!
Dr. Robb