This is in reference to purchasing Microsoft Office or Adobe Creative Suite or any of the products within this scope.
Here are some factors to consider when purchasing new software.
One Time Purchase
The Initial Price is low; because it is monthly and usually requires a 12-month commitment.
There is one large payment of the product.
Upgrades and Updates
Upgrades tend to be included in the subscription. The latest software is usually available at no extra cost.
Most likely if you would like the latest version of the software you would have to make a new purchase or purchase a renewal.
Premium Support tends to be included and is active once the subscription is active.
Though you may get support all the time, premium or an express form of support may be available for a shorter time.
So before buying some new software determine what options work best for you.