Wordpress is free (a bunch of files you install), but can be a bit of a chore to keep up to date. And if you end up using a bunch of plug-ins, some of them might stop being updated.
Another option is Squarespace. They charge you every month ($8/mo if you pay for a year at a time, I think), but they keep everything up to date and working smoothly. I'm using it myself, though not for a business website. Check it out and see if it's worth the money to skip the headaches.