もう少(すこ)し安(やす)くなりませんか。

This is a polite way to ask for a discount or a lower price, often used when negotiating or trying to get a better deal, especially in markets or small shops where bargaining might be possible to save some money.

値段(ねだん)をもう少し(すこし)安く(やすく)してほしい時(とき)に、お店(みせ)の人(ひと)に丁寧(ていねい)に尋ねる(たずねる)表現(ひょうげん)です。