Events
Registration already knows who they are.
Somebody registering is already known to you, so the price they see is their own and nobody looks anything up. Their place, what they paid, whether they turned up and what they took away all sit alongside everything else you know about them. Nobody is charged the wrong rate because a list was out of date.
Charge the right rate without anyone checking
The system knows whether someone is current. Pricing and eligibility follow from the record instead of from an honour system at the door.
Keep one roster from registration to attendance
Who registered, who paid, who turned up and what they attended all sit on the same record as the rest of their history.