I'm not knowledgeable about your market or how your product works, just interested in technology and discussions here, so take this at face value.
To me your product looks like a service. I'm skeptical of any service that is a one-time payment versus some type of subscription. With a subscription I'm inclined to believe there's maintenance. With a one-time payment, I'm inclined to believe that either the product isn't sustainable without growth, will become ad-supported, or will fold.
