That is all going to depend on the website and what you expect to be your content.
It also has a lot to do with the skill level of the people putting the site together.
I have had that conversation with many customers. They tend to go with the lowest bidder, and most of us bid on an hourly rate. Halfway through a project they realize that between site rework and exceeding scope they usually find that they should have based their decision more on experience and less on hourly cost. The rates I charge for my team can be pretty high, but normally we exceed expectations and complete the job correctly - Ahead of Plan. So in the long run it would have saved them money to go with the experience. We would have completed the job on or ahead of schedule and very seldom do we require rework.
For a standard couple of page website, I can put one of those together in a few hours depending upon the content and whether it will be hosting videos or not. If videos are part of the design you will need a couple of additional hours to setup and design the video player. That is of course if the video material has already been prepared.
I have had customer sites that were linked to large databases and the sites were completely dynamic that have taken me and my team months to complete. Much of that time was spent getting the data systems normalized and put together in such a way that they supported the website well. Plus insuring that the security of the site matched or exceeded the requirements of the data that was being stored. Depending upon the type of site, security alone can be a gigantic factor. It all depends on what the expectation is for the website.
Other customers after the initial meeting and story boarding the initial site design, we have completed the site in a weekend. That included preparing all the graphics and images, structuring the site in HTML, designing all the CSS and writing the JavaScript for the site interaction. If the site is merely a presentation of ideas and demonstrations those are not difficult to complete quickly. When you start dealing with customer data and money the whole game changes.
My training site, that I have been running for over 3 years, is still not complete, I am always tweaking the design, improving keywords and descriptions, and especially adding content. My videos that I host take on average 10 to 12 hours to complete a one hour of presentation. I have hundreds of hours of videos on my site, so you can imagine the time involved to put all that together.
So as you can see there is no definitive answer to that question. If I were to meet with you and you spelled out your expectations, sat through a site design meeting, and we defined what you wanted to accomplish with your site, I could give you a pretty good idea as to how long that would take. By the way that is not an offer, I am way too busy. But that is the process a professional web designer will go through with the customer. That meeting usually is conducted over two meetings and depending upon the size of the site can take anywhere from 4 to 8 hours to complete.
I hope this helps,