The OP's location is SFO.

LX SFO-ZRH in booking class S in February costs $1300 return, according to ITA Matrix, and will earn 100% on A3 which will be about 11500 miles.

ZRH-ATH-(Greek island)-ATH-ZRH on A3 will earn far more than 500 miles, easily meeting the requalification criteria (not that there is any need to requalify in one trip alone unless the only flying you ever do on *A is a yearly Greek holiday)