I think that any car with 100k+ miles and/or 7-10 years on the clock is going to be expensive to maintain, unless you can do a good portion of the work yourself, or you choose not to do any work at all and drive the car into the ground.

It's also not realistic to expect these cars to be perfect well into their teens and twenties. There are exceptions (I just saw a beautiful 300D with near 200k on the clock), but I'm willing to bet that a fair amount of time and dollars was invested in keeping those cars in pristine condition. My car is, frankly, in pretty ugly cosmetic condition, but I still enjoy the sheer act of driving in it.

With respect to your particular car, I don't see why you need to do a head gasket along with the timing chain cover. I did my timing chain cover a couple of years ago myself for around $50. Even if you took it to a mechanic, it would probably be ~$200-300. I can't fathom why you would want to spend $1,000+ to do a head gasket unless the head gasket was actually leaking.

Part of owning a high-mileage car is being judicious with your repair dollars. Instead of spending $2000 on a head job, I paid an indie $200 to do the valve seals. Yeah, my car burns oil, but 1 qt in 1,500 miles is not worth $2000 to me.