March 30th, 2008,11:22 PM
Depends what you want to end up doing. If you want to work on commercials then Flame is a good move. If you want to do films then you're better off learning fusion. I wouldn't recommend learning Fusion as a route to get to Flame.
Flame costs more because it has a bunch of features combustion lacks and also runs on a system that allows very fast interactivity. It's aimed mainly towards the commercials market where the sessions generally have lots of clients in that want to see a lot of versioning in a short space of time - something that isn't practical on a desktop system with longer render times.
Some extra features you get (over combustion) include some nice keyers (the master keyer and modular keyer), Batch (which is essentially the Autodesk version of a node tree like Fusion), a fully 3D working environment inside action that allows you to use camera's, 3D object and textures and import/export data between many 3D applications. The list goes on...