It is hard to tell exactly what he is doing in that first sentence. A motor home is a large bus-like vehicle with living space inside. Prospects means people who are potential buyers and it seems that the person is selling land or vacation property.
So he has a planned route that is in a circle throughout the area that is for sale and he stops to let his clients look at the nice views.
Makes a loop in this context means he travels his planned circular route.
everybody buys everything on price
Yes, the writer is saying that many salesmen think price is the most important factor. But as a former industrial salesman myself, I don't believe this is true.
If it were true then the lowest price would win the contract every time.
To me there are three key factors in selling: price, quality, service
You need 2 of these to be successful in sales