The shop has about 500 autographed copies of the book available for purchase.
这家书店有大约500本该书的签名版本可供购买。
《柯林斯英汉双解大词典》
2
In this case, having to then let go of the book after holding it might generate a subtle sense of loss, and motivate us to make the purchase even more.
在这种情况下，拿着书后不得不放手，可能会产生一种微妙的失落感，并促使我们购买更多。
3
I encourage readers to go to their local library when they can't afford to purchase a book.