What are the costs involved in shipping by ocean freight?

I am looking to understand what changes and costs apply when shipping our products by ocean freight. I have just started a company that manufactures Hydraulic Power Presses. I recently received an order from Australia, and since the equipment is heavy, I will need a container to ship it. However, I have no idea about the shipping costs and whether they might be expensive. Has anyone shipped heavy products by ocean or air? I would really appreciate any help or advice.