 J Sainsbury PLC LSE:SBRY recent round of price reductions will eat away at margins, according to Credit Suisse, which has kept its underperform rating. but raised its target price to 200p from 184p, Credit Suisse predicts somewhere between a 10 to 20 basis point reduction in retail operating margin 0.1-0.2 over the next three years based on recent Kantar data and Sainsburys latest promotion, where it promised an additional 50mln investment, taking its current commitment to 550mln. 