Hi Rhonda,
Are you talking about advertising on FB or just posting on your business page on FB?
"i was under the impression that people posted on facebook all the time....for free!" - yes, they do. The pricing you are talking about is only for advertising.
When you set up your FB page, you do get asked for an ad budget, but this is optional. You can click the 'skip' button on the bottom right corner of that screen and continue with your free business page.
Let me know if I've misunderstood or you need any help setting up your page.
Sahiba