How about 'free'? Cheap enough for ya?
Go to your COntrol Panel, open Printers and Other Hardware. Open Printers and Faxes, you'll see there's a wizard to set up a fax driver.
Load it up. After you're done, pick the 'Add Local Fax Printer' in the Printer and Faxes page.
Once you've done that, you'll have a new option, the ability to pick 'Fax' as your printer when you're printing. Scan your document, pick Print, and pick Fax as your printer.
I see you have a modem, so you'll be all set. You might want to pick Fax while you are in the Printer and Faxes page, right click on it, pick Properties, and tell it which modem to use, but you should have no problems figuring that out.
That fix you up?