对于网友的这个问题，我与前面两位老师的看法有所不同，但有些地方我也没有把握，提出来向大家请教！对于网友的句子，我的初步理解是（即同意网友的理解）：

The price was higher than he wished to pay.（正确用法）

The price was higher than the price that he wished to pay.（是否符合语法值得怀疑）

网友的句子出自《剑桥英语语法》的p1121（可参考黄网友的截图），其标题是：

Unexpected cases of upwards percolation 向上渗透的例外情况

也就是说，此内容主要讲述一些向上渗透的“例外情况”，其中一种情况是比较项为名词的后置修饰语。例句如：

They would have us face risks greater than President Kennedy’s most influential advisers seem disposed to face ___.

He made tables of veins, nerves, and arteries five times more exact than ___ are described by any contemporary author.

The gaps here require understood NPs, not AdjPs, since their functions are respectively object and subject: the comparative phrases must include risks and tables of veins, nerves, and arteries. Consider also the following, where the AdjP in the matrix is predicative rather than postpositive:

《剑桥英语语法》认为这里缺省的成分需要理解成名词短语，而不是形容词短语，因为它们的功能分别是宾语和主语，也就是比较短语必须包括risks和tables of veins, nerves, and arteries——注意作者认为这些都是“向上渗透的例外情况”，而非“错误情况”。

接着《剑桥英语语法》提出还要考虑以下情况，其中主句中的形容词短语是谓语而不是后置修饰语：

This result is better than ___ would probably be achieved by a vaccination policy.

The price was higher than he wished to pay ___.

When children start school they tend to get books that aren’t as rewarding as they’ve had ___.

The eastward movement of the Atlantic thermal ridge was forecast to be a little less than ___actually occurred.

该书在这些例句下面给出的解释是：

Again, the missing element from the comparative clause must be understood as an NP, not an AdjP: they are equivalent to “... than the result that would probably be achieved ...”, “... than the price that he wished to pay”, “... as the books they’ve had”, “... than the movement that actually occurred”. It is questionable whether such examples are frequent and systematic enough to qualify as grammatical; certainly the construction illustrated here is not generally permissible, as is evident from the clear ungrammaticality of *This candidate was much better qualified than they appointed (“than the one whom”), and the like.

该段开头用了 Again 一词，表明它是承接上面一段而写的，上面一段提到“这里缺省的成分需要理解成名词短语，而不是形容词短语”（这些是“向上渗透的例外情况”，而非“错误情况”），所以这里用 Again 表明，此处比较从句中缺缺的成分也必须理解为名词短语，而不能是形容词短语（这些也是“向上渗透的例外情况”，而非“错误情况”）。同时注意，这里作者用的是 they are equivalent to（它们等价于），而不是“它们应改为……”“符合语法的表达是……”等，这表明作者是在用后面的例子对上面的句子作“解释”，即上面的句子“等价于”（而不是“应改为”）：

“... than the result that would probably be achieved ...”

“... than the price that he wished to pay”

“... as the books they’ve had”

“... than the movement that actually occurred”

接着作者说“这样的例子是否使用足够频繁和足以构成体系以至被认为符合语法，这是值得怀疑的”，这里要理解的关键是 such examples，它是指有 the price that 等的句子，还是指没有 the price that 等的句子，我们暂时不确定；接下来作者说 certainly the construction illustrated here is not generally permissible，这句话的关键信息是 the construction illustrated here（这里用于解释的结构），用于解释的什么结构？我觉得就是指“the+名词+that”这种结构，也就是说，certainly the construction illustrated here is not generally permissible 的意思其实是指“这里用于解释的结构（the+名词+that）通常是不允许的”。但问题是作者在最后又来了一句：as is evident from the clear ungrammaticality of *This candidate was much better qualified than they appointed (“than the one whom”), and the like. 这可能是让人产生误解的主要原因，作者说“这从 *This candidate was much better qualified than they appointed (“than the one whom”)等句子的不合语法这一点可以看出”，这句话给人的感觉是，前面的 The price was higher than he wished to pay 等句子跟这个句子是一样的，是不符合语法的，但问题是：既然它们是一样的不符合语法，为什么后面这句加了星号，而前面的句子不加星号呢？既然是一样的不符合语法，那就应该都加上星号。注意，《剑桥英语语法》在前面是有一个“符号约定”说明的：

但本节内容的最后一个例句也是让我感到疑惑的地方（如何理解，向大家请教）。我觉得后面这个句子之所以不符合语法可能与它的主语指人有关，若改用事物作主语呢？它也不符合语法吗？比较：

《剑桥语法》认为不符合语法：This candidate was much better qualified than they appointed.

请大家看看是否也不符合语法：This article was much better written than the teacher required. / This is a much better written article than I have read recently.

很想听听大家的意见！