The engine & tranny on almost any vehicle if properly maintained & not abused should last the life of the vehicle. There are Lexus owners with over 350,000+ miles on their cars and still going strong so I wouldn't worry much about mileage.
Over time and as a car ages I think alot of common problems tend to be electrical gremlins, exhaust, suspension and possibly service to the air conditioner will be required.....the ladder being wear and tear items.
How bad is the collision repair that you need? Make sure it's done professionally & use OE replacement parts would be my best advice.