Not at all. You can buy a good, reliable, well maintained car for $3,000. Mileage is less important than maintenance history. The Focus is a particularly good choice IMO. They are reliable, pleasant to drive, and Ford made gazillions of them so you can get them repaired anywhere and parts are cheap.
You can also buy a basket case for $3,000, so you do need to have a bit of an idea of what to look for (or what to avoid).