[RedDevil]

Hi Paul.

Google is your friend. I've seen complete HID sets for less that $25 on alibaba.com, yet shied away from that because of delivery time and customs and shipping issues.
Also I do not use PayPal (yet, maybe later).

Several shops over here sell those kits for < 50€; I got me one of those.
It had the wrong plugs, after a hassle with the shop I got the right plugs with a free set of lamps.
They were the wrong color, but still nice as spares. If I ever need them; HIDs typically last for 6000 to 8000 hrs burning time.

Yes, HIDs take a few seconds to get as bright as the halogens they replaced and a few more to get near their full strength. Also you need to clear the lamp units more often; condense does not evaporate and snow does not melt because it hardly emits any heat at all, bright as it may be.

The HIDs draw less power so the voltage drop in the wiring should be less. and the regulating units that come with the set will do the rest. There is no drop in intensity when I key off, despite a 2V drop in voltage.

Over here cars sold with HIDs need beam heigth auto-adjust and automated lamp unit spray cleaners and typically have a double sized window spray tank because of that.
Aftermarket HIDs are exempt from that ruling, as it is almost impossible to retrofit those extra measures on cars that were not designed for it while HIDs do increase visibility.
You need to check your law on that, what makes sense over here might well do so in the UK too.
It might even be one of those European laws bestowed on us.

With HIDs you can choose the color 'temperature'. I chose 5000K which appears chalk white. I already had LEDs for running lights that were 6000K (slightly blueish) that were a big color mismatch with the halogens, but the HIDs look almost right.
I thought the color difference would not matter much, but once you see it it itches.
If I had to do it again I would buy both HIDs and LEDs with a lower temp color (4300K, sunlike white)

Cheers, Bart