Pardon my ignorance: What does it mean that "a supplier has registered a component"? What component registry are you referring to?
Do you ever get visited by a representative from a distributor or component manufacturer? Well, this person gets a kickback fee for any component you design in from that manufacturer for that specific design. They go through great lengths to trace a design back to you in order to get these kickback fees to pay out. OTOH, if you bypass this system somehow, they might want compensation for the time they invested in supporting your design. If you needed a lot of help 'for free' then it is possible they actually invested quite a bit of money in you which they intend to earn back through component sales.
I don't have any problem supporting those who invest time in solving a problem. But making false claims is an other matter. Some are honest and ask you if they can register the components for which you request a quote. The question is how to deal with the sharks or how you do this?
One option might be to state some bogus project when asking for quotes so they have no idea what's going.
Thanks! I was not aware that's a thing. Sounds like a business model inspired by shady real-estate agents, who claim exclusive rights to houses they have never been commissioned to sell...
Funny how mention real estate agents. The worse people in sales are car sellers and real estate agents. Make use of each and every possibility to withheld information. They will attempt lying when the evidence is in front of them printed black on white. When confronted they will revert to something like: ah yes (gets nervous), I see. I got confused with that other house/car I was selling today... Time to leave the room.