Back when it was Regents, you could get a "concentration" basically just by getting an above mean score on a GRE subject test. Since I believe the guy who started the Triple Nine IQ Society had about a dozen of them, that became a bit of a fad. I picked up English Lit, Sociology, Political Science and History -- yup, accredited as long as you say it's a "concentration" -- in a year for chuckles for slightly over a $1000 total back when the economy was good to add to my traditional two majors. I always had a sneaking suspicion the college hated our guts for making fun of the process and we may have screwed it for other people. You can still get credit but, offhand, I think it's more like half a concentration for a score significantly better than mean.
Nonetheless, if you pass several GRE subjects tests, I imagine that's still a lot of elective credits received very, _VERY_ cheaply.