You only have to buy one of the two options. Both the subscription or the pack (one-off purchase) give you exactly the same thing:
- up to 10 days data (wave data is limited to 7 days only).
- the Graph Editor.
- more map styles.
In the future, as we add more features and data, most will automatically be available through the subscription but may have to be bought as a separate pack, depending on the on-going costs.
For us, we like subscriptions because it gives us a predictable income stream that we can use to make future development decisions. Essentially, if helps the development especially when server and data costs are monthly costs.