We hope to add a trial period in the future to account for that case. The subscription is really for someone that wants access to all of our extensions but doesn't have $1000 or more to buy them individually.
It is also for someone who regularly purchases all of our products and updates and would rather have a fixed charge they can depend on than have to evaluate each update individually.
It is also for us, since a lot of the power of our tools comes from using them together, we want to make it easier for someone to have everything rather than constantly accounting for users who have one product and not another.