Event price to have a membership discount when events are unaware of membership

I have a bit of a design pattern issue. Say I have a module called "Events" which has the following class:

public class Event {
    public string Name { get; set; }
    public decimal Cost { get; set; }
}

Now say I have another module called "Membership" which has a dependency on this module. This is a basic membership module where if someone subscribes to a membership they will receive a discount of the cost of the events.

The problem I have is how do I get the correct event cost in the Events module taking into account the discount when the Events module has no knowledge of the Membership module.

One idea I come up with is to add a service in the Events module, e.g.:

public interface IEventCost {
    decimal GetCost(Event event);
}

Then I would implement this in the Membership module. However every time I display the event's cost I would then have to inject the service and call the GetCost method passing in the event. I'm not sure I like this idea and I was wondering if there was a design pattern to handle this scenario.

I'd really appreciate the help.