what's the difference between coil overs and lowering springs, cuz there's a big price difference....

Lowering springs will keep your car at the same ride height.
Coil overs are adjustable.

For both there are a lot of cheap versions and are piles of shit that are not meant for your car even tho they will say they are.

Everything you'll need to know can be read in here...

http://www.automotiveforums.com/vbulletin/showthread.php?t=276008

thx