I'm a plumber, self employed.
I have to put this into perspective...
I lose jobs all the time, usually over price, when unknowing customers go for the lowest bid without considering risks of liability and lack of experience.
In a world full of liability, high stock prices, increasingly larger bills for overhead/insurance, I find myself often cornered by homeowners or zealous new GC's that often don't understand the risks & expenses involved in my work.
I'd be happy to give my thoughts on what he's doing, how he's doing it or how long it takes him to do it.
However, I cannot possibly imagine giving you an accurate assessment on costs for a job thats thousands of miles from where I am.
I can only hope that there isn't someone I quoted asking someone thousands of miles from me to rationalize cutting corners for me either.
My advice to you...get other estimates in person, check licensing, insurance & references if needed.
I will hint...the price WITH fixtures doesn't sound that bad.
You can get lower, but you can also get apes to type a novel for less than a professional writer as well.
This isn't a hotel discount package, this is your home.