Prices of product variants are not migrated
"Product variants were migrated correctly, but on the front end there is no differentiation in prices for product variants."
Such shopping carts as Interspire, PrestaShop differ technically from shopping carts like Magento or CS-Cart in setting prices for product options. In Interspire you set the price for each product variant separately, in Magento, CS-Cart the prices of product options are calculated according to basic product price. Due to these technical reasons Cart2Cart doesn't support migration of product variant prices. You should handle this setting on your own after the migration.