For $70 you may be able to get a better answer than we can provide looking at a photo.  Mars Wisdom Panel is a DNA test that I have found to give very good information on my own dogs, and dogs I have fostered.  But, the more mix your dog is, the less satisfying the results of the test.  I get mine from Amazon – look for the 2.5 or 3.0 version, they are the newest and give more info than earlier versions.

I have tested 5 dogs so far, and have been delighted with the results. 

Looks like a mix to me.  Does he talk a lot?  Is he stubborn?  Is he totally devoted to you, or is he aloof?