Automator workflow to print 4 copies of 1 image on 1 page
Set up your Automator Recipe

Try doing this to set up Automator: 


Create a folder named "Photo Booth To Print"
Open up the Automator app 




Now inside automator...


Go to File->New and choose Folder Action.
You'll see this bar inside your newly created (still blank) automated workflow: 
Activate the dropdown menu, and find the Photo Booth To Print folder you created in step 1, and select that.
On the left side, you'll see a search bar. Search for "Print" and choose "Print Finder Items". Pop that into your workflow (i.e. drag Print Finder Items into the center part)
Press Command-S to save this Folder Action, and give it a name. Automator will save the Folder Action, attaching it to the selected folder. Now whenever you place anything into this folder, the document will print automatically. (Be careful with your newfound powers, you don't want to accidentally print stuff!)
Double-check you did this right by two-finger-clicking on the Photo Booth To Print folder in Finder and choosing Services -> Folder Actions Setup. (If you only have a few Services, you may not have a Services menu and will instead see the Folder Actions Setup menu item at the bottom of the contextual menu.) The dialog box that displays will show all the folders to which you have attached Folder Actions. When you click on the folder name, you’ll see the Folder Actions assigned to them.




Now use this with Photo Booth

Now, at your party, pull up Photo Booth and take your photo (I recommend taking using the first mode of three listed (the leftmost in the photo mode selector options) to get four photos taken at once, put into one compiled photo. Once you take this photo, it'll show up in the bar beneath the photo frame; from there, two-finger click on the just-captured photo, choose export, and export it into the Photo Booth To Print folder, at which point it will print automatically.



Sources and see also 


Lifehacker's guide to making a DIY photo booth with Automator and the Photo Booth app: http://lifehacker.com/5689177/diy-photo-booth-using-a-mac-and-automator
Source of Automator Information: http://www.macworld.com/article/1167277/software-utilities/three-great-folder-actions.html
Learn more about what Automator can do: http://www.macworld.co.uk/how-to/mac-software/what-automator-can-do-for-you-3605538/