Having different subscription plans makes sense in two scenarios. First, if each module is itself a service that a customer might subscribe to on it's own then it makes sense. Second, if you are charging based on metered usage like AWS.

In the first scenario where each module is it's own service you could construct subscription plans for each and provide discounts to incentivize customers to use more than one module. If these are just add-ons to a core service then I don't think this is a good idea. It just makes the decision more complicated for your customer.