Why do you think the value of computer hardware purchased online was so much greater than the value of books or clothing purchased online?  

Because computer hardware has a lot more use compared to books and clothing.

Explanation:

Books and clothing only have one function. (to contain text and for fashion/comfort)

But computer hardware has more potential for its application.

For example, we can install a PDF software in our computer and completely eliminate the needs for books since it can be used as a replacement.Not only that, computers also can be used to generate profit that can return all the initial cost of purchasing it. (For example, you can use it to create blogs and use ad sense to get some profit). Because of this, I think purchasing computer will be more valuable compared to purchasing books or clothing.