There's an old saying if you recall, "You get what you paid for." Well, only paying $5.71 per sq.ft. for a hardwood floor installed including the cost of the flooring, seems ridiculously low. There is a bunch of chinese imports these days, in all the markets. I suspect that that is what you are getting for that low price. The finish isn't great and the quality of the wood? Who really knows? Ask that salesperson what species of wood it is and I'll bet you they don't know. Ask them the botanical name of the wood species!
Furthermore, you obtained all this info from whom: a salesperson, who's job is to sell you something! Personally, I would be sceptical. But that is my nature anyway. Stick with the brand names and well-respected dealers.