The high price is due to brand dealership which brings certain benefits like it's a actual BMW dealership, supposedly less hassles if you have issues with the car, they can offer as a BMW CPO, provide full disclosure about any accidents, have more staff on hand to service you, will follow BMW industry standards etc...
You just need to decide if any of that matters to you in your buying decision.
If you buy from a non BMW dealership, ask them if it was in a accident and then besides seeing the car report and checking out the car closely, get a BMW Inspection II for your self protection and piece of mind.
If you find they either didn't know it was in a accident or upon close examination notice alot of touch up was done, consider not buying it.
Be prepared to shell out some $ if the BMW inspection comes back with a laundry list of issues. Again, up to you to decide at this point.