Nevermind, another comment mentions AWS. You seem to pretty much run at cost then (a little less), if you GPU hours are $0.432 @ 2 cores, 32G, and a k80. Then packing a p2 instance would run you $7.2 (or $14.4, etc..) and back of the napkin math says you can pack about 15 gpu jobs in a p2.8x. So you hour cost on a job is $0.48.
Just an observation :).