I deal a lot of music instruments (especially violin bows). The difference in quality between a $5 bow and a $10 bow is extraordinary. I used to buy the cheapy bows that lasted a few months then tried out the $10 bows and for $5 more you get MUCH better quality wood, hair, and handle that makes a huge difference. So for paying a little more, I get a much better quality.
This is all up for interpretation. But most of the time in a normal (a.k.a. you are not getting screwed) transaction, the more value you put in, the more you get in return. If you buy a new car, are they going to give you the sport, premium, luxury packages for free? No you have to pay for them and those are the things that make your car better.
Off topic lol
HID kits should only be used in housings that use true projectors. That housing you posted is just a H6024 housing with a fake projector lens that does not do anything. A projector magnifies the light straight onto the road while that housing uses a reflective system which is hard to control the light spread (and you can blind people). With REAL projectors you can control the focus of the light (light spread).
Here is an interesting video on retrofit HIDs.
http://www.danielsternlighting.com/tech/bulbs/Hid/conversions/conversions.html
Bi-xenon= high/low