Where to get HID for 2nd Gen prius? Other than dealer.

Well, first off Gen2 Prius in the US were only built until 2009 and according to your profile you have a 2010 Prius. I don't have enough experience with Gen3 headlights to help. But assuming this car is a Gen2 and the year your car was built is in error, these stupid HID headlights suck in every way!

Day before yesterday the nearest auto parts store in town quoted me the outrageously stupid amount of $149 for just one bulb. And how do you know it's the bulb, not the ballast or the type of bulb as you've clearly demonstrated...

The best solution I always tell people is to spend $150 on a pair of replacement lenses/case that hold standard type 9003 headlight bulbs and rewire the system using Dorman Headlight Sockets 84790. Once that's done you and the future owner will have all kinds of headlight bulbs to choose from that will work without issue and no more stupid ballast that's main feature is ripping people off due to lack of compatibility with other headlight bulbs.

 

If you have a 2006 -2009, use the D4R. I've had this brand in a 2005 for over 4 years with no problems.

D4R Bulb - Factory HID Xenon Series | Onyx Performance Lights

Select a set instead of single and select 4300K for stock replacement brightness. I think they're about $70 for 1 set.

 

That's a good price... Do you have any sense how often the failure of one of these lights is actually the bulb vs. how often it's the ballast?

 

I take care of 3 Gen 2s with HIDs and have never replaced a ballast...over a period of 7 years?