I dream of being a full time writer

Lately work and stress over finances has really been intruding on my once serene mind, causing chaos all around me.My daughter looks at me strangely, my wife wants to kill me and as life tries to pull me in many directions at once and all i want is to write the days away.
Just won the contract to run my own massage clinic within the biggest health retreat to be built in Australia. It is tucked away in a little place called Rolystone which is nestled among beautiful hills and a river covered with lillies.I have eight months to set it up, but then it will run itself easily and not only free up more time for me but give me that financial stability that has until recently been so elusive.
I have been writing heaps and am just re editing at the moment so there will be more Burden filtering through than the last few months.
How long should it take to write a book?
Dean Koontz usually writes four a year.
Australian writer - Tim Winton writes one every five years.
So far i have taken seven months but that is only part time.
What about you, how long does it generally take for you to finish?
By finish i mean polished enough to post on Da or make available for the masses.