It is primarily not about the number of pages
It is about the quality of the pages, then we talking about numbers
As everything else, it also depends on. Like my crazy big landing page as example, it is constructed with so many sections that probably should be enough for three standard pages. The price for that is not the same as the price for one simple page.
My webpage is an award winning page.
I asked some web companies about what it will cost to build it up. The answer is between 20-30.000 dollar.
Many people asking me about jobs. Please think about that I not working for 500 dollar. My time is expensive so I not sell it for a cup of coffee.