Urban Decay Backtalk is a neutral mauve with a satin finish that is discontinued and retails for $18.00. In comparison, YSL Arlene's Nude (121) is a neutral mauve with a satin finish that is limited edition and retails for $38.00.
YSL Arlene's Nude (121) is 85% similar — it is less shimmery, darker, warmer.