Supporter and subscriptions


I have supporter set up and slightly hacked on a BP and MU install.

This allows everyone free access to the BP features but if they want to make a blog they are forced to a payment screen rather than having the option to say Not Interested.

Now the problem is, I want to offer 30 days trial which supporter does but the huge issue is that once the 30 days in up the user can just continue to login and use everything as it was. i.e: It does not prompt for payment / subscription.

I have tried the membership plugin but I need the site to be fully and freely accessible to the public and it is only the blog creatiion and features that I want to be part of an annual subscription.

I have also tried pay to blog but this does not allow free days.

Any advice on this? I may be willing to pay someone to hack supporter so that it does this.