Deny purchase of bundled product

Hi there!

I’ve googled around to find an answer but I don’t understand if there’s a way to deny a user purchasing a product which is in a bundle product.

The only way I see to prevent purchases of those products is setting a ridicolous price, like 1,000,000$ but I wonder if there’s something better.

If I leave the price to 0 it’s very easy to guess the id of a product and get it for free, you only need some brute force until you get the ID of the product /checkout?edd_action=add_to_cart&download_id=PRODUCT_ID