Menu not updated after role purchase
You cannot disable menu cache - if you could, Drupal would need to scan all modules on every request and it would kill your site. You can use Cache Actions:


  It currently provides actions for:
  
  
  Clearing Drupal cache bins
  Clearing CSS/JS cache
  Clearing The cache of specific views
  Clearing The cache of specific panel pages
  Clearing The cache of specific mini panels
  


Just clear menu cache in the same rule you use to add a role to your user. After adding that role, of course.