AMS at your service

I contacted this company because it was local and it could handle my need when I made the appointment. When I asked about the costs, I was told, «there is a $ 19.95 service call fee, then the locks start at $ 19.95 for most locks, but could go higher depending on the lock.» I then asked about just re-​keying the lock, and she said that it would be the 19.95 fee.
The locksmith called in advance to verify our appointment, he arrived on time, and was friendly and ready to work. I showed him the doors, and he told me that he would replace each lock with an dead bolt lock. I asked about the cost and he said each was $ 85.00. I was not expecting that, especially for 5 doors. When I asked about alternatives, he said that replacing each core would cost me $ 19.95, but for some locks I needed two cores because of a key used on the inside. Still the cost would be below nearly $ 450.00 for the dead bold locks. After some talking, he lowered the cost to $ 70 per door, and the service fee. I asked for an exact fee because we were getting the cash together (he preferred cash instead of check or credit — curious), but when he finished and came time to pay, he said the total was $ 420.00. I asked him to repeat because I must have misheard him, but he repeated the price. I said, that is not what we agreed, and I balked. I told him that I had asked for an exact price, and he had told me it would by $ 370.00. Finally, he took the money, saying, «Okay, well the customer is always right.» He gave me a receipt and left.
His service was terrific, but the shady practices for pricing and lack of an upfront cost should have made me more wary.