This age BMW, with this particular engine is one of the last BMWs that is shade tree tolerant. The car has low level oil and coolant lights. They dont consume HGs normally. Stuff has to break then be ignored to cause an overheat. To over heat to the extent of blowing a head gasket pretty much means the head warped,and will have to milled. Yes, it is a nice car , but to pay to have this job done is more than the car is worth. You also have to find and fix the root cause of the overheat. This is a perfect DIY project. With normal up keep , this is a 300k miles + engine. But you have a 200k engine with a warped head and who knows what else wrong with it. So a used engine is an option too.