PS: I have a BS from small and inexpensive college and at 28 I got promoted to the same job as the 27 year old with a BS and MS from MIT I sit next to. Now we both went to college, but if you compare the sticker price of his education he got a much worse deal then I did. Granted, 10 years from now he will probably make more than I will because he works ridiculously harder than I do.
You assume that because you have the same job and sit next to each other that you make the same amount of money. In my experience that is a very unsafe assumption. Unless you know what he makes, you don't know that. (In most US companies, talking about what you make to co-workers is a fireable offense for a reason.)