What is the difference between grid and calculator parameters in pricing calculators? / How do I know if an option should be a grid or a calculator parameter?

Differences between Grid and Calculator parameters:
1)  Grid parameters allow you to enter a set price into the grid; Calculator parameters allow you to tell the system how to calculate the price.
2)  Calculator parameters are easily edited if you need to add more options; Grid parameters are not easily editable.  Once the grid is created, you can't add options to it or remove options from it.
3)  Grid parameters can only apply to quantity 1; Calculator parameters can apply to any quantity parameters that you have created in the pricing calculator.
Tips for determining if an option should be a grid or a calculator parameter:
1)  If you have only a few options (besides quantity) from which your customer will choose, use the Grid Parameters area to enter the option name, and the choices your customers will choose from. If you will be providing many options with many selections, you may want to enter them in the Calculator Parameters instead.  With many parameters and many options, the Grid method can create a very large table with cells you will need to fill in. 
2)  If you have options that will change frequently, such as paper types, you will want to add those as calculator parameters since the grid doesn't allow you to add additional options.
3)  Start with a list of the options you would like to offer and then how the price for each option will be determined.  This will often lead you to the best type of parameter.   For example, if you have a combination of choices that lead to a final price - such as size and paper type, then using a grid parameter for size and paper type might be best.