Is $7,000 to refinish 715 sqft of maple hardwood floors a fair price?

I am having my maple hardwood floors refinished and noticed numerous swirls and scratches from the sander after the first coat of stain. My wife and I believe this is not acceptable for the price and would like it done properly. The contractor was extremely angry and thought the finish was perfectly acceptable. I was concerned that my wife and I were being unreasonable based on his reaction. He told me he finished with 80 grit, but everything I've read suggests maple needs to be sanded to 100-120 grit due to its hardness. This contractor came highly rated, but he is the only person who does this sort of thing in a 100km radius in my area, southern Ontario, and his rates are double the high end compared to other rates in Ontario. We noticed the major imperfections after he applied the first coat of stain.