I checked out JAWS for Windows and was surprised by the prices. (Although that may include Braille support.)
For those who wish to have their Mac read a file – including a PDF – simply press Command-A to select the text, then choose Services > Speech > Start Speaking Text. (There’s also a Service to tell the computer to shut up.)
I haven’t checked a multi-column PDF to see if that creates problems. But if so, make a text copy of the PDF using Data > Convert > To Plain (or Rich) Text. Then select all the text and choose the Service as above.