Customer group change on item purchased (reoccurring)

Currently I am adding customer to customer group manually.

Ideally I want the customer to be added to a customer group automatically when a certain item is bought. Ideally a reoccurring item.

I am thinking to basically check whether the item is in the customers order list and if so then set the customers group id to the correct value.

But for a reoccurring item would I be able to access whether it has been renewed per say or not? Because I would like to demote the customer out the group if not.

Is there a simpler way of doing this? Better way?

Thanks

Well, this would not work, at least not by default. one would have to
re-design the entire system, to make something like this work.
Ernie

It is possible to make it without redesigning the whole system. I have an extension Group Fee or Discount, which promotes and demotes customers, but not when item is bought, but when particular number of orders with defined total made. It is basically the same you want, but with different conditions.

I doubt there's an extension for your task specifically, because it's quite custom. So the only way for you is either code everything yourself or pay for the job.