Oprah Winfrey -- You're Paying Too Much For My Old Crap

You paid too much! And you paid too much! Everybody paid too much for Oprah Winfrey's old junk at her estate sale today ... and the Big O was shocked.

Oprah and BFF Gayle King were front and center during the auction Saturday in Santa Barbara ... where she was selling stuff off for her Leadership Academy in South Africa.

The first item was a poster (pictured below) from "The Color Purple" that Winfrey proudly displayed in her office for a long time -- the starting bid was $2k ... and Oprah was blown away by the price.

The poster eventually sold for $4k --but you have to see O's reaction as the bids went up, and up, and up ...