Disclaimer: I have no affiliation with this company other that I use it for MailCharts (http://www.mailcharts.com/).
Edit: Your first license with iubenda is free: https://www.iubenda.com/en/pricing
the terms don't change and I can't think of any good reason to pay monthly, except of course that iubenda makes more money that way!
not everything needs to be crammed face first into an SaaS model
There's a free, yearly or monthly subscription. The subscriptions really just divide a bigger chunk of money into smaller very affordable bits.
If you need the basic, free bit, perfect. Otherwise the SaaS system is in place for us to deliver a sophisticated service at very little up front cost. If you keep using it you get the updates pushed right to your app. The license can be reused on new projects, too.