The way they create quotes is extremely deceptive, the estimated weights especially for book boxes will be well under what the actual weight will be and they will then charge extra after cartons have been collected.
Make sure you weigh your cartons if you pack yourself. The quote for 5 teachest cartons and 3 book boxes which I received included a weight of 140kg, 17.5kg per box. A 3/4ths filled book carton weighed 23kg when packed.
They are however pretty professional and helpful. Their quotes are just deceptive.