Of course, when it’s gone, it’s gone.
If you wait, lifetime billing may no longer be available. And, if you buy now, you risk losing out. But this decision is no different to that the early adopters made when committing to Roon 6-7-8 years ago. To me, this is an easy decision: if you’re prepared to risk losing $829.99, buy now. If not, go for a subscription.
But, you should be certain Roon is right for you, and halfway through a trial may be too early to make that call.