is it bad to get a car with over 100k miles...wat is a good amount...

it depends on the car and how fast those 100k were put on the car. Overall maintenance of the car is alot more important than mileage alone.

Just look for a high mileage car that has had LOTS of new parts put on. You don't want to buy a high-mileage car with a lot of original parts....I learned that the hard way. :/

Let us know the car, engine, and year. I would buy a Toyota Tercel with 200k on it, but I wouldn't buy a Rover with 50k on it.

It entirely depends on many factors. There are also always exceptions to the rule. You might get a lemon Toyota (like my wife's Tercel) or a good Rover (like my neighbor's Discovery with 300k)