double[] values = {250.99,0,250.99};
>bool valuesEqual = values.Where( v => v != 0).All( v => v == values.Max() );

dim values as double() = {250.99,0,250.99}
>dim valuesEqual as boolean = values.Where( Function(v) v <> 0).All( Function(v) v = values.Max() )

dim valuesEqual as boolean = (values.Where( Function(v) v <> 0).Distinct().Count <= 1)