These are sold - thanks for all the interest.
I have a set of FSD's (Koni Kit P/N 2100-4036) I used for just under 7K miles. I replaced them with a full Dinan Stage 3 suspension set-up.
FWIW - Overall I really liked the FSD's and they perform exactly as advertised (improved ride and control) - certainly an improvement over stock sport suspension (2009 e92 335i with factory sport suspension). The only minor criticism with the FSD is the combination of sport suspension and OEM run-flat summer tires would occasionally allow the fronts to bottom out on really severe potholes or bumps (we have some pretty bad roads in the NY/NJ area). This was not a problem with my winter tires which are not RF's so a more resilient tire helps.
I am asking $450 plus shipping. I will absorb PayPal fees at my asking price. Local pick-up is also welcome - $400 for cash + local pick-up so we both save money. I live in Northern NJ ZIP 07059