Im playing on TVHM and I can confirm they do drop, I got 3 before I even met Piston.
Not particularly worried about losing my cash though, I don't ever seem to spend any so its just weighing me down lol
Target 40k - Hit 18/12/2010
Target 50k - Hit offline date unknown
Target 60k - Hit 19/10/2014 (Brain Drain - Borderlands TPS)
Bioshock Infinite: Clash in the Clouds - Blue Ribbon Guide