The following code provides an example of how you might show a variant original price and the discounted price on a cart page or slide out drawer. This will display the crossed out original price (also known as compare_at_price) and the discounted price.

{%- if item.product.has_only_default_variant == false -%}
{%- if item.variant.compare_at_price != item.variant.price -%}
<div class="cart-item__discounted-prices">
<span class="visually-hidden">
{{ 'products.product.price.regular_price' | t }}
</span>
<s class="cart-item__old-price product-option">
{{ item.variant.compare_at_price | money }}
</s>
<span class="visually-hidden">
{{ 'products.product.price.sale_price' | t }}
</span>
<strong class="cart-item__final-price product-option">
{{ item.variant.price | money }}
</strong>
</div>
{%- else -%}
<div class="product-option">
{{ item.variant.original_price | money }}
</div>
{%- endif -%}
{%- else -%}
{%- if item.original_price != item.final_price -%}
<div class="cart-item__discounted-prices">
<span class="visually-hidden">
{{ 'products.product.price.regular_price' | t }}
</span>
<s class="cart-item__old-price product-option">
{{- item.original_price | money -}}
</s>
<span class="visually-hidden">
{{ 'products.product.price.sale_price' | t }}
</span>
<strong class="cart-item__final-price product-option">
{{ item.final_price | money }}
</strong>
</div>
{%- else -%}
<div class="product-option">
{{ item.original_price | money }}
</div>
{%- endif -%}
{%- endif -%}