How did you get around suppliers/mfrs wanting to pick and choose whether they think your product is worth their time or not???

Looking to hear what you might have done to get a supplier to listen and make your product. It's been evident for many years that suppliers would love love love to have a cargo ship load of an order. The reality is they still have to prove themselves and their skills. It's already known that they want to work with projects that use materials they already have too. They don't want to hardly lift a finger it seems beyond anything basic and common to them. You cant just approach a supplier and lie to them about the size of your order because you don't want to ruin them as a contact/source. It seems to not matter if there's $10 million in the bank waiting to go on a purchase order, they still seem to want to pick and choose. My own project is a unique product. It's been months trying to get suppliers to listen, literally. The surprising part is this is a very very basic/simple product yet they still try to sift through like they know how your project is already going to turn out. In short,they are not the decision makers. It actually helps them move to the back of the line if I see those tactics. Any thoughts/ideas? Thanks