When should I file a provisional patent vs. full patent?

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. Not legal advice.
Hypothetical question

EDIT: added more context below. Hardware startup, built a novel sensor mechanism. Investors asking about IP protection. Heard about provisional patents being cheaper. When does it make sense to file provisional vs going straight to full patent?

Illustrative response

filed a provisional 3 years ago. never converted to full patent because we pivoted away from that tech. saved us $15K+. that's the real benefit โ€” it's basically an option to file a patent, not a commitment

Illustrative response

honest question: are patents even worth it for startups? I've heard big companies just infringe anyway and dare you to sue them with your $0 budget

Illustrative response

Fair point. Patents are worth it when: (1) you're in hardware/biotech where copying is expensive anyway, (2) investors require it (common in deep tech), (3) you're building for acquisition (acquirers pay premium for IP), (4) you're in a space with contingency-fee patent litigators imo.

For pure software SaaS? Usually not worth it. Trade secrets + speed to market is better strategy.