It really varies as to where you live in the US. We're in the mid-south and it was $2 sf to install prefinished. Had it been site finished, it would have been $4-6 sf. (basically $2 sf for install, $1-2 sanding, and $1-2 for finish application) So, depending on where you live, that quote might be very reasonable. The best guage for your area is to talk to several experienced contractors to see what they would charge, and also ask the flooring shops how much they charge for a site finished install. Tip: Ask for references or to see previous jobs and see if the owners are/were happy with the install job. If they don't know what they are doing, you can have a big mess quickly. So $1-2 per sf extra to get someone who has a great rep and knows exactly what they are doing might be the better deal in the end.

It can be quite a bit more on the east or west coast.
Maybe some others will chime in here...

There is not a one price fits all jobs, and there is not a one price fits all contractors.

The companys quotes, are what they need for the business to make a profit, along with paying everyone, what they are worth. Cheap labor has you putting out fires, instead of making profits and gaining good references.

The business profit and the business owners profit/wage are not the same thing.