Pricing of Air Freight
Due to the on-cost of carrying any surplus kilos on an aircraft, weight (not volume) is the main basis on which air freight rates are charged. Only if you have an oversized item does size become a key factor in pricing.
Air freight forwarders have the advantage that they are able to offer purely weight-based charges, while couriers normally charge extra for each individual item that they have to account for.
If you can get your goods to fill or near-fill the standardised Unit Load Devices (ULDs) that fit the front hold, you will get the best rates. Their internal dimensions are (approx.) 307 cm long x 213 cm wide x 193 cm (max) high.
Whereas there is a competitive market for Consols, Direct consignments are subject to agreed TACT (the Air Cargo Tariff) common carrier rates that most airlines apply.
At the time of writing the market is depressed and prices are competitive, despite high fuel costs.