I would say it's about right for the mileage. You can probably find a better deal though for a few K more.... A little less miles, still under 30K.
Of course, this all depends on the cars background....
i'm looking for around 25 - 30k that leaves me with a little extra cash for some corsa exhaust... i'm obviously not rich as hell and won't be sending it to lingenfelter or hennessy...