(Reuters) - Champagne can only be produced in the French region that bears its name, but the joy that comes from hearing a cork pop can come from any number of other sparkling wines - at a fraction of the cost."The central problem is that wine pricing is almost completely arbitrary ... the price of a wine does not significantly correlate to the pleasure it brings," said Robin Goldstein, editor of "The Wine Trials," an annual guide to wines under $15 a bottle that beat wines costing $50-plus a bottle in blind tastings.