In the release announcements for any new version we usually have demo or active site links that are using the new version.
If you wish us to perform an upgrade on one of your sites instead of you doing it yourself you would just need to purchase the proper services.
You would need a members area renewal for 39.00 no matter what. That would allow you to gain access to the new code and at that point you could upgrade your site yourself. Now if you wanted us to do an upgrade on your site then you would purchase an upgrade service for 49.00 in addition to your renewal and we would upgrade your site for you.