Proper Etiquette with Contractor

I am new to the dance and I would like to get some advice on what is the proper way to negotiate with a general contracter regarding a big complicated renovation at a house. I saw two contractors so far and one says he needs a minimum of x grand for the bathroom and the other says he can do it for half that amount. One says he can fix the old hardwood floor and the other says it will look like crap and I should tile it. One says he can paint over the old kitchen formica cabinets and the other says says it will not work. They both have very different opinions and prices about everything. Also, when I asked one to give me a breakdown on the cost of each job he says he can do it all for a certain amount but if I make him break it down it will cost twice the amount. Is this how it works? Is it not proper to expect a price breakdown for each job big to small? Also, they both want the entire job while I feel like farming off some aspects of it to different people if I can get a better quote on windows or floors for instance from someone.

By Phalces |