The one-time $49 fee is cheaper than replacing a battery. A new MacBook battery costs $199–$279 from Apple. Even if you extend your battery's life by just one extra year, AlDente Pro pays for itself 4x over.
If the Pro license cost is a barrier:
When you search for "top" license keys — meaning popular or frequently shared keys — you're likely to encounter: aldente pro license key top
Cracked versions of AlDente Pro circulating on torrent sites and keygen forums have been found to contain: The one-time $49 fee is cheaper than replacing a battery
If you genuinely can't afford $19/year, consider AlDente (free version) — it still offers basic charge limiting. Or try open-source Battery Toolkit (less polished but free). If the Pro license cost is a barrier:
AlDente Pro offers a 14-day free trial with full features. That's plenty of time to test whether Sailing Mode or Calibration is worth the price for your use case.