[JWait]

I'm not sure I follow you but here goes. "Our Price" is the price the customer will pay. If there are any Product Options (either "Price Modifier" or "Product Variant" - look in the Product Options section of Product Management in admin ) that change the price, that is what "Our Price" will display.

Probably the easiest way to list a "Base Price" is to have a Product Option "Price Modifier" or "Product Variant" field named "Base Price" that has no added price variation. You can list "Base Price" as the first "option" available to the customer by position (OrderBy in your options list) or by selecting it as default (DEF in your variants list) and this is what will be displayed as the default to the customer. If the customer chooses an option that changes the price, then this is what they will see as "Our Price".

I usually reserve "List Price" to be what X-cart calls "Market Price", by changing the language variable. I don't really see a need for a custom extra field, as a the extra field will probably be displayed for every product, regardless of if you want it to or not.

Maybe I am missing something in what you want to achieve, if so please let me know.