WooCommerce: Hide price and variations

I’m searching for a solution for my woocommerce-problem.
The shop I’m running is about plants. The different plants have different variations, for example different sizes. I used “grouped” products to show the different variations in one product. So, when you click on the product, you can chose one of the first size, two of the second size and so on.
My main-problem now is that I do not want unregistered users to see the prices AND the variations. They should see the product (picture and description), but they should not be able to chose how many they want, so that they don’t see the prices, but I haven’t found a suitable solution yet.

The plugins I tried were until now only able to hide the whole product-pages oder the whole shop, but not part of the product-pages.

I hope someone has an idea. Thanks.

Use s2member plugin in combination with sidebar login plugin. s2 gives you a better user/member management and sidebar login allows you to hide certain pages if logged in or not.