You can purchase product X if you purchased product Y

Hi,

What you can do is this:
- create a new joomla user group named "has bought product Y" (or something else) via the Joomla user groups manager
- edit the product Y, and in its "user group after purchase" setting, select the user group you just created
- edit the product X, and in its "access level" setting, select the user group you just created
That way, product X will only be accessible if the current user is logged in with a user account linked to the "has bought product Y" user group, and this user group will be added automatically to the user account when he purchases the product Y.

Hi,

That's correct.
Now, instead of using the "access level" setting of the product, you could instead use the "access level" setting of the price of the product and turn off the "display add to cart button for free products". In that case, the users who didn't purchase product Y would still be able to access the product X page but they wouldn't see the add to cart button and wouldn't be able to purchase it.