Which script(s) allow me to lock monthly fees?

I could realy use some tips on which membership site scripts allow me to set a monthly fee for, let's say, the first 50 members and lock this fee, while members 50-100 pay a higher monthly fee and so on...?

 

You could use the password, subscription setup through paypal.com.

 

Or you can use any CMS and code a modification to do it.

 

Let somebody create you the script.

 

use Joomla...use AEC...change the subscription price after 50 users...