Contact Chris at Zygmunt Motors:http://www.bimmerparts.comHe also goes by CMUZYY over at bimmerforums.comHe was pricing the springs for $288 plus shipping...this was back in March.( http://forums.bimmerforums.com/forum/showpost.php?p=8933818&postcount=3 )understeer.com did have them for $280 but now I see they are $315.
if your running races upgrade to konis or go home. billy sports are only a good valve match for sport springs, not races.if anyone tells you otherwise then they don't have much person experience to back it up.