How can I show or hide the prices?

In Also Bought it is possible to control the visibility of the original prices and the sale prices. 

These options can be found inside the 'Prices' section, in the Visual preferences. There, you can control the visibility and appearance of product prices and sale prices:

The first option will be the one to show the prices.

In the following image you can see a working example of this option:

It is  important to be aware that if you decide to uncheck that option and hide the prices, all prices in the app will be hidden.

As you can see in the following image, there are no prices showing on the app:

You can also choose to show a 'Compare at price' when available (make sure you also select the 'Show prices' option)

This will make the app look like the following image: 

If you click the 'Advanced style options' link, a new menu will display with different options to configure the style of the prices so the app matches your store theme. You can read more about these options in the related articles.