Match the color?
In the past, when I need to paint one portion of a car and I want to match color, I take the gas door to the paint shop and ask them to match it. In less than an hour, their computer tells us all of the components needed to match the color. It spits out a formula of the various shades reqd to match.
Admittedly, removing a prop is not as easy as removing a gas door but if someone has the prop off and is willing to bring it to their local paint supplier, you could share the formula with everyone and end the monopoly/overcharge.
Paint suppliers also sell refillable shaker cans.
Barry