I have a 2002 Focus wagon 5 spd.
Look out for rust near: rocker panels, rear bumper reinforcement, wheelwells, rear suspension (nearly inevitable), door bottoms.
Wagons sometimes eat rear tires if the alignment is off, ask about this and get it checked. You may need to to get it adjusted and buy adjustable camber bolts or control arms for the rear.
Clutch is not super hard to replace but it isn't easy either. Count on a full day's worth of work to do it and 200-300 in parts, depending of if you replace the flywheel too.
Other than that it is a great car and you can hold a lot of stuff. When I get home I can measure the width of the rear cargo area. I would really recommend it as long as you are willing to do basic work on it yourself. You shouldn't have a problem with it at 150k if it has been well maintained, only minor things here and there. The dent in the rear bumper can probably be pushed out. Just warm it up with a heat gun or a hair dryer and the push from underneath.