the sandwich responsibility

I want a ham sandwich, but I'm only able to spend $3 on it. I walk down the street looking for someone willing to sell a sandwich to me for that price.

Jill sells ham sandwiches but wants $5.

Ben was selling them for $3 but is out now.

Sue sells watches.

Mitch is homeless and doesn't even have a store.

Which of these people — possibly more than one — is responsible for my inability to buy a ham sandwich?