No, you don't have to pay again. When you go into your account to see your alerts, you can deactivate it whenever you want before the date of the reservation. You can also edit, but you can only edit the notification preferences and your party size. It does start at $5 but it may vary depending on how far out you are from the reservation date, so I made an H&V alert last week for 12/1 and it was $6. I also made an alert for the Plaza on 12/3, but it was $7. It found a Plaza reservation for me, but I'm still leaving it activated to see if there is a better time available. Overall, it's the best reservation finder I've used.