What is a good amount of mileage

Depends on what you're looking at... type of vehicle, usage, etc... any specifics on the vehicle you're concidering?

Sorry ..jumping in .. I have similar question. I'm Planing to shop second car and budget is limited and my thought is buy new models though high miles . This is my opinion and factors i consider - mostly Age is defining factor of condition of anything either car or human. Rather than buying 10 yrs old car with less miles with old technology which is about to rattle in next 3-4 years / fall apart (like hoses, rubber cracks, oils stales ). Buying new one makes sense the worst could happen in new car is transmission , shocks, break ware out- this could happen to long sitting car also. the point is - if your driving is less then 30 miles - it takes 10 years to put another 100K and when you trade in you get more value irrespective of mileage. take the analogy of actress - new actress always in demand .