depends a lot on exactly what kind of drop you want. on my mk3 Cabrio, i wanted a 2" drop w/ close to oem spring rate as i didnt wanna sacrifice the ride quality. i dont do any "performancee" driving. i just wanted it lower. i dropped about 200 bucks. if you wanna go stiffer or lower, it will be more expensive.

BTW there's a set of B&G Lowering springs for your car on ebay for 100 bucks + 40 shipping. i say at that price you cant pass it up. not sure how low they go but for 140 bucks i say get em. (search B5 Audi Springs)