Hide prices of a certain product category to non logged users

Hello all!

I need to hide the prices of an entire product category, just if user is not logged.

One of the brands my client is going to market, forces her to require registration/login to show prices; its mandatory.
I need something like this guys are doing: shoprescuespa.com/shop-by-skin-type/dry.html -> as you can see, some products have a 'log in' button instead of 'add to cart'.

Also, I cannot see any registration/login built-in functionality within Marketpress, is there any?

Thank you all!

Javier