I made up a preliminary offer on Facebook. What happens just prior to finalising the offer they email you a copy of what it looks like. I downloaded it from one of my gmail accounts with Firefox. If you want the original kosher facebook version you have to use Firefox to download it as other browsers don't allow you download a webpage in its correct format. Then I opened the downloaded file in Dreamweaver and edited it as needed.
So you can make the offer without paying Facebook fees and just have a link from your facebook page.