You can take the first 50 lbs for free. Then they charge you for every 50lbs after the first 50. You cannot use anything but re freezable coolants or dry ice, no ice. If you use dry ice you can only have like 5 lbs per package so that will get very pricey. You have to adhere to their container rules as well. Call Southwest, they are more than willing to explain it all to you and are very helpful.