Complaint Review: ANYTIME GARAGE DOOR INC

The company gave me a ballpark estimate $150-200 for spring replacement over the phone. That sounded pretty reasonable for me. Today technician came to my house and was surprised that I have such a heavy door (24Ga double steel back and front) and explained to me that I need a special spring to hold that giant. He gave me three different options: $288 with 1 year warranty, $388 with 5 years warranty and some other option which I was not interested in. He also told me that the 1 hour of labor would be $140. When I asked him why the total price is so different from the estimate. He explained to me that this is because of my enormously big and heavy door.

And at this moment I made a mistake I let him do the job. I am so upset that I have not ask a second opinion. 

Finally he finished his job. When I walked into garage I realized that he replaced both springs when only one was broken. On my question "why???" he explained that the other spring was damaged as well and he decided to replace it without asking me. BUT he was so "generous" and have not charged for that but put it in a bill as it would be under warranty. 

At this moment I have got a suspicion. Why he is giving out $388 thing for free? is it just because he is so good guy and want to make me happy? 
I gave him a credit card and he left. When I checked the prices for the springs with absolutely identical specs (0.250 x 31 x 1.75) I was shocked. The price for the same thing was in a range $35-$60. 

I called the company, complained and let them know that I am going to put a bad review on yelp. The guy on the phone said - "Go for it." 
It's totally my fault that I have not made a research before and have not send him back and did not get a second opinion. But I want to warn other people.