I agree but a grey area (pun unintended) exists at the low altitudes we rotary folk are often required to operate at.
A lot of light aircraft and rotary wing (albeit away from your area, over lower terrain and under the London TMA, for example) are often obliged to fly in IMC, but do not fly high enough to use quadrantals, nor are they able to climb higher.
You and your colleagues should push hard for TCAS; you might be surprised how useful (and interesting!) it can be. Even the police aircraft are now widely so equipped. I mention that because I know as an ex-police pilot (and ex-SAR boy too), they are always very much budget constrained but saw it as a priority and did obtain it some years ago. I've operated for over a decade with it and wouldn't like to go back to flying without it, especially when under IFR in these days of decreasing LARS cover.