Alexcfer,
We offer a 10% discount to users that are extending active subscriptions, however we don't offer any discounts once your subscription expires. Support and other maintenance issues on our side go down if user's keep their subscription and extensions up-to-date. Once it's expired, the need for more support to 'catch up' grows similar to that of a brand new user.
As for integration with jFusion and PHPBB, we've helped multiple users get that combination setup before. There are a few different options that we've heard of that make things work smoothly, but each site is different, so it sometimes takes a little trial and error. We'll gladly help you however we can if you decide to re-subscribe.
Thanks,
Alex