Yes it is going to be expensive (about $600 US) since it requires the replacement of the whole Display Assembly. If you have AppleCare+, then you can have it repaired for $99 US.
FYI, I have replaced the bezel on our organization's Macs, but it is a very difficult process since the glass is brittle and there are lots of very fragile and easily damaged cables directly beneath the bezel. Even installing the replacement bezel is difficult to properly align it. Unfortunately Apple doesn't supply a replacement bezel even to their service providers so only bezels pulled from other broken laptops are available. It is not something most techs are able to do without lots of practice and no authorized service provider would be allowed to do the repair due to Apple's strict rules concerning repairs.
Since the damage is already done, you can try using some black electrical tape (cut to size & shape) to cover the broken section of the bezel to attempt to prevent the crack from becoming worse and to protect the exposed cables.