Just FYI, hard sided cases with their packing materials typically weigh over 30# empty. By the time you add your pedals and bottle cages, you'll have to have a pretty lightweight bike to get it under 50# in a hard case. So, with that in mind, if the airline offers that same deal on international flights, you'll definitely save money using a cardboard crate. I've never used one and I'd be kind of afraid to, myself, but if you let the LBS pack it up for you, hopefully it should be okay.
Speed comes from what you put behind you. - Judi Ketteler