Trading up isn''t just for the wealthy anymore. These days no one is shocked when an administrative assistant buys silk pajamas at Victoria''s Secret. Or a young professional buys only Kendall-Jackson premium wines. Or a construction worker splurges on a $3,000 set of Callaway golf clubs.<br><br> In dozens of categories, these new luxury brands now sell at huge premiums over conventional goods, and in much larger volumes than traditional old luxury goods. <i>Trading Up</i> has become the definitive book about this growing trend.