HardProfits - I did consider something like this, but unfortunately Verotel don't let me link to a specific product. The only option is a drop-down box with a list of prices, so you see everything configured. If I had been able to 'deep link' into the join form then I would have created a special price and linked to it in the mailout to the affected members.
I'm still considering a second mailout to the people who haven't re-signed, maybe in a week or so, offering them a couple of bonus sets if they sign up again.
It was important to move quickly as I was losing more rebill income every day.