Come up or Step up to the plate

When we talk about a plate, we don't mean a dinner plate. A dinner plate would be full of fish, salmon, and catnip. That would be my cat's plate and not mine.

When I think about a plate in this context, I think of a baseball plate. You have to walk up to the plate to be in the safe zone. Coming up to the plate means to basically to put your money where your mouth is. If you can handle the challenge, then you can step up to the plate.  You can meet the satisfaction or demands of the other side.

Let's look at an example from the TV reality series Pawn Stars.

Will see if these guys are willing to come to the plate and play ball.

 Now this sentence is a little worded differently, but it means the same thing except they didn't use a phrasal verb.

The heavy-set man with the purple shirt just wants to know if these guys whom he wants to sell his junk to are serious and will pay the price for what he wants it for.

Here is the video below. Remember, they're many ways to say this sentence. I have given you the way I would say it.