Hi, Cindy. It's impossible to tell what work has to be done and how long it will take without seeing it. For what it's worth, the rate sounds reasonable for an urban area.
Two things that I suggest though are that you replace the hoses that come with the washer with stronger "burstproof hoses" and that you put a pan under the washer for when it overflows. Notice that I did not say "if it overflows"--it will someday. The plumber should be able to tell you where to get these before he starts the job.