You can make a DIY 70W hqi for under 40 bucks..The bulbs on ebay are like 15-$20, they last 2 years+ depending on useage, and depending on your reflector and bulb could crank out 12000+ lumens. Also you could get a complete 70W HQI aquarium fixture for less than $150. and as far as LED goes, you can buy a complete fixture that cranks 5000 lumens for under 100 bucks.
Okay then that does help distinguish the difference between Xenon Halides(automotive grade HID) and HQI Halides(aquarium grade HID).
I read that the reason in the difference is purely environmental saftey because of the mercury gas used in other types of halide bulbs such as the HQI.
Still my main goal for reviving this is to see any real hard info on the xenon HID lights exists. I have been looking at the differences between the types of halides, but my brain is fried so I'll be updating this when I can.