Abstract
As you know OpenCart will show the price of your products in every list o search result, product form, etc.
Sometimes that value is used in a formula, but do not represent the final price, it’s more like a “starting at” price.

Idea
Slightly change your theme or search for language files in OpenCart and make some modifications in order to show the string “Starting at” near every place where price is showing.
Then, in your formulas, near the first line (to better reading) add a user variable to store the real base price for that product, that will be the price used in your calculations.

Regular way: Dummy example using actual Price of the product
If you use a price per m2 for example, it will be confusing to show that price to the customer

$FinalPrice = {14} * {16} * $Price;

Trick: Dummy example using a Price to show and other to make the calculations
Tricked Price will not be shown anywhere, the customer can not see it, but you can use it in your formula.

// You can store for example a price of 12 in that product, indicating that this product
// has a price "Starting at 12".
// But in the formula we use the price per m2, for example
$TrickedPrice = 46;
$FinalPrice = {14} * {16} * $TrickedPrice;

You can visit this demo in our Demo Store