Change import script for modified oscommerce

Normally, products price (and tax class) are added throug easypopulate.php. On a shop in development the products have multiple prices (per size). These come from the products_plant table and are stored in the plant_price column. This table is filled through the [login to view URL] script. That script doesn't take count of the configured taxes in oscommerce (or the modified oscommerce that is used). This needs to be changed so that it processes the taxes.