This is a bit of a complex question to answer, but assuming is a typical service based business website where you are using primarily for SEO, Marketing, and informational purposes - the cost is or should be very relatively low. Depending on the type of build you prefer, whether you hire a developer who knows SEO to build your website natively friendly with SEO or not will affect your final price. Not every designer is a good developer or good SEO person. But I would say, even with SEO for a basic informational website with good SEO structure should be no more than $3,000 usd... custom designing and complex animations or backend data entry would of course drive the cost up. We did some service informational sites in the past that ended up racking the clients' total to $30k. This isn't common but they were a big client with complex systems on the backend while the front end was informational only for guests.