“二价”怎么读？

“二价”的英语可以翻译为：divalent，bivalence，bivalency，dyadic，bivalent ...

我们都是不二价.Our prices are all fixed.他说这白菜概不二价.He said he won't accept any bargaining for the cabbage.你能便宜一点卖 么 对不起,不二价.Can you come down a little? -- Sorry one price for all....