Like cars and kitchens, diamond engagement rings are now being upgraded — either re-fashioned or replaced — by affluent consumers.  Styles change, disposable income often increases and some women tell their husbands that their original rings now hurt their fingers.  There is also the notion a “pushing present” for women who recently give birth to a child.  Jewelry designer and HSN guest Carol Brodie first detected the trading-up trend a decade ago.  “It didn’t necessarily mean bigger, it didn’t necessarily mean better — trading up means more about lifestyle.”  The Canadian Press Jun. 1, 2010