Depends on the work and time anyone would need for the work. Also depends on the backend(WordPress/SMF) and type(ASP, PHP) of website you want.

I charge $50 for modifying website user interface and speeding up sites for Search engines and visitors :3 And $70 for full setup and basic SEO.

I know people who charges $3000 to 4000 for creating websites from scratch! Responsive designs are in demand nowadays so cost increases too :P

Usually, $100 to $5000, depending on the designer's status, time required, etc is what it costs to design a website (From my experiences)