Help hidding price for specific products within collections

Hello everyone!

I am trying to remove prices from product cards only for specific products. I tried apps and they work, but they slow the rendering speed of the prices I do want to show, and this has been confusing costumers.

I have tried adding a specific tag to those products, and using the following code in the product-card.liquid file, but it is not working either:

 {% unless product.tags contains 'coleccion-privada' %}  {% render 'product-price', product: product_card_product %} {% endunless %} 

Any ideas on how I could do this by adding code and not using an app? Maybe using a different parameter?

Thanks!