How to politely say "I'm not doing that for free"

Thanks so much for considering me. Here is a link to the services and price packages that I offer. Let me know if you have any questions.

This sounds like a great opportunity, thank you for considering me. Are you able to confirm that this is a paid opportunity?

I appreciate you thinking of me for this opportunity. Unfortunately, i’m unable to take on any unpaid projects at the moment but i will circle back if that changes.

Thanks for reaching out! I typically charge a flat fee for this kind of advice so I’m unable to answer this via DM’s but i’ll drop you a link below where you can consultation with me.