Septic tank replacement - main sewer line connection

I live in Cobb County, Georgia(Metro Atlanta). Recently my septic tank leech fields started failing. So I paid the county 4k to connect to public sewer. Next I have to make the connection to the sewer tap. The first quote I received was 4200 to connect the main sewer line and 900 to collapse the septic tank. Does anyone think this is a fair quote? Obviously I am going to get a few more quotes. My house is 80 ft from the main line and there really are not any obstacles like trees in the way. The elevation is fine and I will not need a pump. I read on Home Advisor the average is between 900-2500 so I am a bit perplexed at this first quote. I'll get another quote and see but I assume most of the guys have an idea what the other guy will quote.

Every area is different and without seeing the minimum other two quotes, I really don't think it is fair to answer at this time. We have no idea what the job consists of, the soil you have, the depth of the lines or the connections which will need to be spliced.