Chartering a vessel is not something to take lightly if the individual or group does not have the experience and the team in place at both ports in order for the whole affair to go smooth. Delays costs a great deal of money. Every hour the vessel is in port and not being loaded/unloaded costs thousands of dollars.
The most cost effective way to ship large quantities of any commodity is to charter a vessel. To ship 25,000 MT in containers would be impractical and expensive. It would take 1,250 containers to ship this quantity.