Like the others said, you are paying for the electrician's know how and years of skill. If it was easy and totally non-dangerous work, you would have done it yourself.
Reminds me of the story where a guy got a pin put in his bum knee by a doctor, during surgery. He woke up and was surprised at the $10,000 doctors bill. He called the doctor over and demanded an itemization of the bill. "Sure" said the doctor. He hastily wrote an invoice that said "One Stainless Steel Pin ----- $1.00 Knowing how to put it in ----- $9999.00"
Why is it that people will not think twice after getting a $5000 bill from a doctor for 1 1/2 hours of surgery, yet will complain nonstop about getting a bill for $373 for an hour and a half of service from an electrician. Peoples' difference in attitude between the two always amazes me.
It would have been common sense for you to get a written price BEFORE the job started. It would have also been wise for you to get bids and prices from several electricians before having the job done.
Let me ask you this.....say you were looking for a car. Would you go into a car dealership and and buy the first car you saw at whatever price they wanted to charge you? Of course not. How is this analogy any different from your electrician situation? The car dealership will charge you whatever the maximum price you will agree to pay, and so the same with the electrician. This is the basic principle of capitalism.
You also do not mention the charge for materials, as this can be a substantial cost depending on the specific job. Believe it or not, it is standard practice for the electrician to make a profit on any materials that he uses on your job, just in the same way that a mechanic makes a profit on any parts that he orders in order to fix your car.
Just let it go and chalk up this experience to a relatively cheap lesson. You are also in a bad way already, since you have canceled the check. Do what you have to do to make sure he gets his money. Besides you being nailed on check fraud charges, you may not realize that this electrician can get a judgement and put a lean against your house if you do not pay the full agreed upon price. You will never be able to sell your property without paying the electrician first. Auto mechanics often set leans on peoples' cars who do not pay up for the auto service that was perfermed on their car.