UPDATE: Download Woocommerce Extra Price Info Pro Plugin to show extra info on cart & checkout pages.

There is no way to add extra information with the price of the product in Woocommerce. So I created a small plugin which adds an extra box below the price input in edit product page.

You can use it to show the extra information where you are selling quantity based products or you can use it even with other products which comes in packages , e.g  $10 (10 pencil pack)

This way your customer will know quantity or the number of items they will get just by looking at the price.

Here is how I added the extra box to show info with price in fronted.

First we need to add the extra box to add/edit product page.It will allow user to add extra info while adding price.
We will use woocommerce_product_options_pricing for that

To save the added info , we will use woocommerce_process_product_meta

Finally to show the added info with price we will use woocommerce_get_price_html

Thats it !!

You can download the full plugin from wordpress repository or you can check github repo