jìrán / shuāngfāng / yǐjīng / qiān / le / hétóng / jiù / bùnéng / yīnwèi / jiàgé / shàngzhǎng / ér / fānhuǐ

既然双方已经签了合同，就不能因为价格上涨而翻悔。

Since both sides have already signed the contract, they cannot renege just because the price has gone up.