With proper maintenance 200,000 is no big deal. Have the trans serviced. It will last much longer that way. GM transmissions are much better than they were in the past. A friend of mine has chevy Colorados and 1500 Silverados for his business. He is careful to do maintenance on them. They are driven by employees so thats not good for them. He has a few with over 300,000 with only 1 needing a trans. He changes the oil every 5000 and has the tranys serviced every third oil change. Several others have over 200,000. No major engine work on any of them.
Here's hoping it's better than our 2000 Chevy Venture. The tranny completely failed at 24,000 miles, while still under warranty.
At 65,000, the tranny now has a sticking solenoid (common problem), and it's going to cost $770 to fix.
I haven't bothered to replace the fluid since it was completely flushed when the tranny was rebuilt.
This is my wife's soccer mom car, so it's not like it gets a lot of abuse.
I also have to replace the leaking steering rack, had the intake manifold problem fixed (common problem), and had the rear wheel bearings replaced at 55K. The 3.4 engine's been rock solid, but it's rediculous how soon some of the other components are failing. Very disappointing.
I'd trade it in, but the trade in values are horrendous on a domestic 10 year old minivan.