well what programs specifically do you need because there are cheap/free alternatives to all of them
maybe offer to pay half of it if you can't get free alternatives? or save up
If he using it for school, the class most likely requires him to learn that specific program.
This isn't something like a writing class, where Open Office could be substituted for Microsoft Office, cuz all you need is something to put words on a page, Photoshop (and other CS programs) is a very specific skill set that the class wants him to learn, because that's by far what is most used in professional settings.