In a sign of how competitive the entry-level sport sedan market is becoming, the BMW 3 series will be offered with a less-powerful engine and lower base price. Look around the show floor for all the reasons why: a new Lexus IS, the Infiniti Q50 and the Cadillac ATS, the 2013 North American Car of the Year. And then there's the Mercedes-Benz CLA, a sedan with sporty coupe styling coming this fall. Nearly a year after the all-new 3-series line went on sale, the 320i sedan, left, hits showrooms in late April, at $33,445, including shipping, to start. That entry-level price sheds some $4,300 from the base 328i sedan. BMW is determined to keep the franchise tag on its prized 3 series -- the world’s top-selling luxury model -- even if it means lowering the base price and shedding some horsepower.