In your case it would be more cost efficient that you would figure our the length of time that you will use premiere pro and after effects. For example, if you only need to use both products for 2 to 3 months, it would be more economical for you to subscribe to both of these applications on a month by month basis. On the next year when you know you will need access to all the apps then you can select to subscribe to the individual or business solutions for the complete creative cloud.
Trust me as this will save you a lot of time in trying to save money by subscribing/cancelling/subscribing on a short-term basis.