If they're like the lights on many cars then you can DIY and save some money. On most cars you remove a few panels, which may require a trim popoff tool but is otherwise pretty simple. The assembly itself is probably held in with a few screws, bolts, or other fasteners, and there will be one or more connectors.

It might take a bit of time, but it's not worth $400. I'd help someone do it on their car for a few beers, so see if you can find someone to help if you're not comfortable doing it yourself.