Q&A

I have 2003 VW Beetle and close to 66k. The check engine light is on, and went to the dealer for diagnosis. On top of an oxygen sensor failing, they found one of the tie rod needs replacement and costing me $700-800 if fix them both. They also said catalytic converter is in bad shape and could fail in near future. The bad is that the cat is under warranty but expires in a few months. I am debating over fixing them at a local place or going back to the dealer. Any tips?
Real question - I had temperature sensor replaced 3 years ago, battery replaced 2 years ago, in addition to regular maintenances. When is the breakpoint that you should consider replacing a car? The current price of the car supposed to be ~$3500 (Blue Book). Will there be major repairs waiting in the next few years?