Killed my subscription before launching. Was that stupid?

I was two days from launching with a €9/month subscription. Then I hit a question I couldn't answer:

What happens to the charts people already published when they cancel?

My product makes 3D charts you embed in a page with a link. Paying removes the watermark. So when someone cancels:

- If the watermark comes back → I just broke a customer's live website, retroactively.

- If it doesn't → paying for one month equals paying forever, and nobody renews.

There's no third option. And I realised the problem wasn't the price, it was the model: the value here is an event, not a service. You make a chart, you publish it, you're done. You don't come back tomorrow.

So I switched to a one-time €19. No renewals, nothing to cancel, no question to answer.

The obvious downside is no recurring revenue. But my marginal cost is close to zero, the embed is a 148 KB static file , so I'm not funding servers that justify a monthly rent.

Has anyone here made this switch? Did you regret it? I keep reading that recurring is the only sane way to build, and I just walked away from it.