1992, Mean Real Gross Income in Euros:
West Germany: 26,408
East Germany: 15,928
Source: 20 Years of German Unification: Evidence on Income Convergence and Heterogeneity by Tilman Brück & Heiko Peters
Meanwhile, income inequality across Germany as a whole actually decreased after reunification because of Easterners getting richer:
While income inequality in West Germany has generally not altered in an [...]