Botox maker Allergan Plc is betting on aesthetics with the $2.48 billion acquisition of fat-chilling device maker Zeltiq Aesthetics Inc., doubling down on a lucrative industry where patients pay mostly in cash for products and services. The purchase price is $56.50 a share in cash, the companies said Monday in a statement, a 14 percent premium to Pleasanton, California-based Zeltiq’s closing price Friday of $49.40.