Around $9 per square feet for NWFA standards craftsmanship on top of your flooring and underlayment cost. The look and feel you are trying to achieve will play a factor in cost.

There are guys out there still doing it for $2-3 per square feet. You will need to decide which is more important: quality or cost.

Good install companies have direct relationships with mills. You can never equal the price of someone who buys hundreds of thousands of square feet over a year. Plus, it annoys most pros that you've inserted yourself into a process that they should control, in order to deliver a predictable end result. They HATE being presented with a pile kindling with bad milling and high moisture content, and to be expected to turn that into a magazine worthy home.