Consumers who surf the Web or flip through catalogs for holiday gifts may pay more than they expect to buy and return merchandise, a UC Davis professor says. Eitan Gerstner of the Graduate School of Management says consumers rushing to order last-minute gifts should consider the extra cost of shipping and handling charges. In most cases, those charges -- and the customer's cost of returning items by mail -- are nonrefundable. In a study of refund policies published last month in the Journal of Service Research, Gerstner and two co-authors conclude that a nonrefundable shipping and handling fee is a somewhat subtle way of offering only a partial refund. Gerstner says catalog merchants use separate shipping and handling charges -- much higher than actual shipping costs -- to disguise the true price of merchandise, to encourage customers to order more and to discourage returns. In an earlier study of direct marketers of clothing, the same researchers found shipping charges ranged from 12 percent to 28 percent for a $25 order and from 1.3 percent to 5 percent for a $350 order. About 90 percent of the catalog merchants did not refund shipping and handling charges, and 70 percent did not compensate for return costs. Only 7 percent compensated customers for all of their out-of-pocket costs.