If you are sure you want to stick with it and believe that Roon will survive another 6 years or so, then yes, monthly is more expensive. I paid for lifetime after two days or so, but it was cheaper then. I just meant that if you are unsure after two weeks, you can extend by a month or so until you are sure.
I don’t think there ever was a 50% offer nor will there be, as Roon has been on record many times to say that they prefer the steady income from subscriptions, and in fact the lifetime option may go away in the future.