And if you are not a student it's a subscription: every year you'll pay up 69 or 99 €, "access to Tower ends when the most recently paid-up subscription period ends."
Not so great... (they switched to subscription some years ago, adios amigos!)
Tower is quite literally the only application I'm willing to pay subscription pricing for. It's quality software, doesn't hold my data hostage, and has a steady stream of updates. I'm as adios amigos as you, but I don't think the usual reasons apply here.