I've had the Crateworks Pro XLC for several years and it has held up well. More importantly, my bikes have come through the trips without damage. www.crateworks.com is one option at $110 to $170 for a case.
I'm not sure what price range to suggest to meet your "not terribly expensive" requirement. Cheaper options include getting wheelbags for your wheels and use an airline box or one from a bike shop. Many bike clubs have hardcase rentals available as a member benefit.