I advice to use import CSV file to add items to the component. It is easy to load import file again when you installed new version. Also you can use SQL script to export items to CSV file.
Use this SQL scripts to export items to CSV file using PHPMyAdmin utilily:
For IPrice calculator LIGHT: items_from_light_plus.zip (see attachment)
For Iprice calculator: items_from_pro.zip (see attachment)
So upgrading process from IPrice calculator LIGHT to Iprice minimart will includes following steps:
1. Run PHPMyAdmin utility and select your database. Run the SQL script to export items to CSV file. Do not forget to change table prefix "jos_" to the prefix of tables in your database.
2. Download sample import CSV file for IPrice minmart:
iprice-web.ru/images/import-rus.zip
3. Insert your data from export CSV file to the sample import CSV file for IPrice minimart.
4. Uninstall old version of IPrice component
5. Remove all tables with "iprice_" prefix from your database using PHPMyAdmin utility.
6. Install IPirce minimart trial.
7. Import items from sample import CSV file.
Do not forget to backup database and files of your site before upgrading process if you upgrade component on a live site.
More details about import in IPrice minimart:
iprice-web.ru/en/iprice-minimart-guide/2.../68-art-import-items