Cars need stuff replaced. That's the fact of owning one, and you'll never get around it. Some cars eat parts earlier than others, and some have expensive parts and others not.
A Protege with 200K that's been looked after is a good bet if the price is right. But, with ANY older used car, have some bucks in a budget for repairs. I don't really consider a timing belt, water pump or any of the stuff people think as "major" as a big deal. A timing belt replacement for most inline fours is about $250 parts and labour. If you can't swing $250 for a repair, get a bus pass. Not being sarcastic, that's the fact.
Between 200,000 and 300,000 that Mazda will probably need some suspension work, maybe a new rad (cheap) perhaps a valve cover gasket (cheap) and maybe a clutch if it's been ridden. (not so cheap) But, buying a $4000 car and spending $1200 a year on keeping it in top shape is cheap compared to dropping a minimum of $4000 a year on a new car.
We had a 1988 626 that needed stuff on a regular basis after about 130K, but nothing that broke the bank and it was much less than the lowest lease payment on the cheapest new car. Now, I'm a little handy and most of the service work and many of the repairs I can do, but some stuff I had the dealer do, and it was still cheap. Plastic rads (all cars have 'em now) tend to wear out sometime after 200K, but on a Mazda, it's usually about $250 installed at the dealer.
I keep my 1998 Mercedes in like-new condition. If a part is even suspected that it might be close to the end of it's life, it's replaced. It gets serviced much more frequently than the schedule calls for and even with my super-duper-anal-ness about not letting anything go, it still runs a fraction of the operating cost of a new econo-car thanks to flat depreciation.
