Letrozole, sold under the brand name Femara among others, is an aromatase inhibitor which is used in the treatment of hormonally-responsive breast cancer after surgery...Wikipedia

Manufacturer's Website: Femara                                                                                                                            Average retail cost: $314/10 tabs

Exemestane, sold under the brand name Aromasin among others, is a medication used to treat breast cancer. It is a member of the class of antiestrogens known as aromatase inhibitors...Wikipedia

Manufacturer's Website: Aromasin                                                                                                               Average retail cost: $1,450/30  tablets

Anastrozole, sold under the brand name Arimidex among others, is a medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer...Wikipedia

Manufacturer's Website: Arimidex                                                                                                                                      Average retail cost: $1,924/30 tabs