THE bigger-is-better concept seems to be striking a chord among some Starbucks customers. Starbucks yesterday began a phased-in US rollout of its Trenta cup size that can be filled with nearly a liter's worth of iced beverages such as coffee, tea and lemonade. Starbucks Corp says Trenta, which means 30 in Italian, will be 880 grams and cost about 50 US cents more than the 570-gram Venti size. The new cups will be introduced in 14 states: Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, Oklahoma, New Mexico, Hawaii, Nevada and Arizona. California residents will be able to buy them beginning on February 1 and the nationwide rollout should be complete by May 3.