Perennial plants on sale in the fall

I became a gardener around the same time that writer Caity Weaver shared a beautiful obituary online for her mom Maureen Brennan-Weaver. Its closing paragraph included a tip that's become a yearly bedrock for how I make my ambitious garden dreams come true:

"In lieu of sending flowers, please plant a little something in her memory. Please also be aware (in her memory) that garden centers mark perennials down to unbelievable prices in the fall."