If you can stretch an extra $30 or so, then either a shure 215 (dynamic, bassy sound) or a westone um1 should do you nicely. The Westone is a single ba driver so won't have the bass of the shure. However the westone with either the blue or red tip trufit included in the pack should do very nicely isolation wise.
Failing that Shure have released a new budget se112 model that is available for $49.00 Claims around 37 db noise reduction.
I sympathise, until recently I was in a similar situation.
Edited by davidcotton - 6/4/14 at 9:20am