I think using base metals will be enough. At worst, they would attempt to eat through the metal, which could take weeks. [Cybertronians do not take big bites, despite appearances. Their food consists liquid of small snacks or shaving of metal. They're like the giant Earth whales in this matter.]

But for now, this will do. Thank you for your offering. [...And now, payment.] Do metal supplies work?

[Otherwise he has to share a secret and he doesn't know how embarrassing that has to be.]