Try the Acrobat forum: this is the Digital Editions one.
Adobe Reader is free anyway, you can't buy it.
There are a few free alternatives to the Adobe Reader for reading Acrobat files, such as Foxit reader.
http://www.foxitsoftware.com/Secure_PDF_Reader/
If you mean Adobe Acrobat, it is more than a reader, as it can be used for authoring/editing files.
There are alternatives to it as well; not sure what they are.