I had to add the filter hook for product variation as well.
add_filter( 'woocommerce_product_get_price', 'pr_reseller_price', 10, 2 );
add_filter( 'woocommerce_product_variation_get_price', 'pr_reseller_price', 10, 2 );
add_filter( 'woocommerce_product_get_regular_price', 'pr_reseller_price', 10, 2 );
add_filter( 'woocommerce_product_get_sale_price', 'pr_reseller_price', 10, 2 );