Using capture & case statement based on product sku

[Houmy1]

I have a quantity discount app and want to show the pricing on the collection pages for the lowest price such as "as low as xxx". I figured for now I would just pull the product SKU and show the price based on that by coding it in manually using a capture statement to assign the SKU to a variable and then using a case statement but it does not seem to work even though I am able to pull the product SKU. The code I have is as follows:

{% assign current_variant = product.selected_or_first_available_variant %}
{% capture skuprice %} {{ current_variant.sku }} {% endcapture %}
{% case skuprice %}
{% when '312-L' %}

As low as $0.42

{% else %}
{% if emphasize_price %}
{{ product_item_price }}
{% endif %}
{% endcase %}

Is there another correct way of assigning the SKU to a variable which I can then use in my case statement? I tried ASSIGN but that resulted in an error.