After purchasing this cleaner system, how long will it take before I need to renew it and pay again?
This is entirely established by the developer of the application. You can check its official website for this information. The price should be displayed in a simple mode (e.g 50 $) or on a period basis (e.g. 50$/month). This tells you the licence period. The information is usually specified on the buy page of the product you're using.