Subscriptions really???

I have enjoyed this app and is one of my favorites that I have used that is however until the recent update. Now you have to subscribe for a monthly fee for the new features that the update comes with. When I purchased the app it was to get the app with the updates that made it better. I wouldnt even mind paying a one time fee for the features of say 4.99 but to pay monthly how much will this app cost over the course of owning it?

Cyylus about Fishing Deluxe - Best Fishing Times Calendar