Lightroom Subscription

If you plan to remain subscribed to the creative cloud then the monthly or yearly payments will continue for as long as you decide you want to use the software. Yes, it is a perpetual payment. No, it will not end if you want to continue to be subscribed to the creative cloud. In the long run, it is a little more costly than purchasing upgrades to the standalone program whenever it is released. But you  have more features and the use of Lightroom Mobile. Really, if you're going to subscribe to the creative cloud then plan on keeping it and using it. If that bothers you, then purchase Lightroom 6 as a standalone. When/if Lightroom 7 is released you will have to pay an upgrade fee if you want  the newer version. And you won't have access to the latest Photoshop if you go with the standalone program. You pay for the Internet every month and don't seem to complain about that. Just consider Lightroom as another monthly expense.

Be aware that your subscription will automatically renew at the end of the subscription period unless you cancel.

More info: Cancel your Creative Cloud membership