An example of showing original product price compared with discount product price:

Note 
The functionality of showing original product price compared with discount product price is the same for both Instant Search Widget and Search Results Widgets.

Shopify:

Go to the Smart Search & Filter control panel > Instant search widget section > Content tab and select the Show compare at price setting.

BigCommerce:

Go to the Searchanise control panel > Instant search widget section > Content tab and select the Show retail price setting.

Magento 1, 2:

Go to the Searchanise control panel > Instant search widget section > Content tab and select the Show original price setting.

Available starting from version 3.1.3

CS-Cart, Wix, WordPress:

Go to the Searchanise control panel > Instant search widget section > Content tab and select the Show list price setting.

For CS-cart, the setting is available starting from version 3.3.10

Please don’t forget to save the changes by clicking the Apply Changes button.

Note
The enabled Discount labels feature overrides this setting.