Going for an example that has the belt done recently is the simple solution to such toughts.
I may drive bangers, but every car I've ever purchased was fresh off service, fresh off the rigid swiss inspection and always from a garage, never from private. Those are my golden rules.
Sure those rules makes a used car more expensive, but to keep the initial purchase costs down I always go for cars that are mechanically in top order, but have dents, large scratches or hail damage.
Has worked so far with every car I had.