I'm going to Disney and want to buy lightsabers and bring them home. Should I send them back by mail or is it cheaper to get a bag for the plane? Thanks

Cheaper if your able to fit it on your carry on which should be able to go under your seat.

Depends on how many lightsabers how much room they'll take up in a bag. Are they going to be in a box? Are you going to take it out of the box? If you're going to take them out of the box, you can carry them on the plane. But if you're not going to take them out of the box mail them flat rate, and it'll be cheaper.