Yes — boxes, suitcases, or a mix.
Yes. You can send strong cardboard boxes instead of suitcases, or mix the two in one shipment — whatever suits what you’re moving. Boxes are often the practical choice for books, kitchenware and household items.
Price is based on the weight and volume, so pack sensibly. As long as your shipment is what you told us, that’s the price you pay, subject to airline rates at the time of booking.