Set span to Shopify liquid Variable

I am trying to set span class “price” to Liquid variable if the if statement is true.

<p class="old-price"><span class="price-sep"></span><span class="price"></span></p>

I have tried this method to see if this “price” class in the if statement overrides the “price” class above because it comes after the above code. I’m new to Liquid but I know in JavaScript there is a way you can set text to “variable”, what is the way with Liquid ?

{% if dynamic_products.compare_at_price_max > dynamic_products.price %}
                <p class="old-price"><span class="price-sep"></span><span class="price">Box 
Value:{{ dynamic_products.compare_at_price | money }}</span></p>