I want to know the good and bad in comparison of cheap 140 dollar and 350-500 dollar HID bulbs. I know about projectors and aiming and glare but i just want to know of any flaws or disadvantages between the two classes.

The expensive stuff is real HID lighting and usually fits and works correctly. The cheap stuff is not always real HID and can be an unholy bitch to get installed and working satisfactorily. You get what you pay for.