You can try handling the CurrentCellChanged event, and saving the value at that point.
private void gridControl1_CurrentCellChanged(object sender, System.EventArgs e)
{
Console.WriteLine("gridControl1_CurrentCellChanged");
GridCurrentCell cc = this.gridControl1.CurrentCell;
GridStyleInfo style = this.gridControl1[cc.RowIndex, cc.ColIndex];
if(style.CellType == "FNumericUpDown")
{
this.gridControl1[cc.RowIndex, cc.ColIndex].Text = cc.Renderer.Control.Text;
}
this.label1.Text = this.gridControl1[cc.RowIndex, cc.ColIndex].Text;
}