Site hosting can be as cheap as $1 a month to hundreds a month.
If you have a static site (meaning one that is never or rarely updated), at large hosting companies (such as GoDaddy), the monthly costs can be between $6 to $12.
Places like GoDaddy offer different flavors of Content Management Systems but you would still need someone to set it up for you. You certainly can do it yourself, but make sure you have the time to learn and can spare losing some hair.
The Content Management System I recommend, Webvanta, costs less than $30 a month and with many great features built in.