I'm not seeing a good upgrade path from 6pro  to 7pro .

Carrara 7 Pro Upgrade from Carrara 6 Pro is  $169.95

Carrara 7 Pro Upgrade from Carrara 6 Pro is $99.93 for Platinum Members.

So if I sign up for the Annual Platinum Membership so I can do the upgrade for the Lower Price, I would have to pay $99.95 + $99.93 = $199.98  which is more than if I simply do the upgrade without being a Platinum Member.

The other option would be to sign up for the Monthly Platinum Membership for $7.95 and than cancel the membership.

The other thing that is strange is that the Monthly membership is $4.55 cheaper over the annual subscription over a 12 month period.  Normally Annual subscription are made cheaper than monthly subscriptions as an incentive for people to sign up.