ここの蔵書の中には、お金で買えない貴重な本もあるんだって。

、。

I heard that among the books here, there are rare ones that money can't buy.

Literal

Here [possessive-の] library-collection [possessive-の] among [in-に][topic-は], money [with-で] cannot-buy precious books [also-も] exist [hearsay-んだって].

蔵書 'library collection, book collection' — 蔵 'storehouse' + 書 'books.' お金で買えない 'that money can't buy' is a relative clause using the potential negative. んだって is casual hearsay: 'I heard that.' The sentence conveys impressed amazement at the value of the collection.