Actually HID's are becoming cheaper.
I'm not anti LED but I've done the math and to replace my HID with an LED that provided the same light it would take almost 5 years to pay for itself. Now granted every situation is different. I grow in an unheated garage during the winter and have cheap power. If I lived in Arizona I probably wouldn't be running HID's. But where I'm at the initial cost outlay doesn't really justify any savings in power. I could make more money than I can save by putting that same amount of money to work for me. It doesn't make sense financially for many people to switch to LED.
Here's what I pay for power.