You could actually do it yourself. Start with the carpeting (you may want to just keep it in the bedrooms). You can do the floors a little at a time (one room at a time).Go to the DIY web site and they tell you how to do it. Also, it is not a good idea to put hardwood flooring in the kitchen because it doesn’t sustain damage well and would have to be replaced. Also, don’t buy hard wood flooring that is on clearance sale because they stopped making it. If for some reason you need to replace a portion of the hard wood flooring you’ll have to do it all over again because you can’t get the same style. You could hire someone to install it, but check them out carefully. Make sure they are insured and run them through the Better Business Bureau to see if they have had any complaints lodged against them.
Ask the builder or carpenter. They are the ones who get it at contractors price. As for putting it in yourself…..how good are you with tools?? Be honest to yourself.
I would stick to carpeting in the bedrooms and just do the wood flooring in the living/family room areas. If you are handy, I have seen this done on many DIY shows and they make it seem easy enough, just be sure to follow the instructions carefully. Otherwise, have a professional do it.