你说得对，这是固定搭配，句子中的 get your money’sworth 不能换成 get theworth of your money。get (have) one’s money’s worth 意思是“物有所值”。如：

The boat trip lasts three hours, so you certainly get your money’s worth.  乘船游览有3个小时，肯定很划算。

What anexciting final it was! The crowd certainly had its money’s worth. 这场决赛真精彩! 观众这钱花得值!

The film wasonly an hour long, so we felt that that we didn’t really get our money’s worth. 这部电影只有一个小时，让我们觉得钱花得不合算。