Kaltura is Free/Open Source software. The license is AGPL.
You can host it yourself or get a hosted edition:
Whatever solution you choose, you have to pay for bandwidth (which can be expensive with video).
Kaltura won't work on shared hosting, but I doubt that any video management system does.
If you really can't use Kaltura, you can upload flv files and use PluginMediaPlayer, but this requires that your users all follow the instructions properly. With Kaltura, they can just upload just about any format and Kaltura nicely converts it.