Wow! You just described my husband except he got his in Management. :)
My sister-in-law got him a very nice Cross pen and pencil set which is still in its box (two years later). I don't necessarily think it was a bad gift if your friend is in a job where he'll use it. My nephew graduated in Business Finance and I got him one as well but I hid it in a very cheap vinyl pencil case with a box of regular pencils, funky little kid erasers, VERY cheap manual pencil sharpener, but I forgot the very cheap calculator I meant to put in there as well (I got all of it at the Dollar Tree). He got a laugh out of it and still received an effective gift that he should have forever.
If your friend enjoys a drink once in a while how about a nice bottle of his favorite liquor? My husband likes martinis and I got him a very nice bottle of vodka (it was Russian and hand-painted with four different pastoral scenes) so it was very cool and I know he enjoyed it. }:)
In any case, even a nice card (my SIL got my husband one that sang the Hallelujah Chorus when it opened and he still laughs over it) and a dinner certificate, especially with his wife in mind, is a nice acknowledgement for their effort. And it WAS a group effort. I know. ;) Whether she watched the kids and kept them out of his hair while he went to class and studied or helped type up his papers or just gave him moral support to get through it she had a lot to do with his achievement as well.
Hope I didn't give too much information but there you go--M.