My seester has a Subaru wagon of similar vintage, it is very nice, solid, fast, etc. In-town gas mileage ain't nothin' to brag about, but on the road is good. Excellent drive train in marginal wx (AWD).
The "24 [mpg] in suburban driving" is, I think, a fantasy. 27 on the highway, *maybe* if the cruise is set and speed is not too high, but real-world "suburban" driving will likely yield about 18-ish. YMMV (literally), but if the buy is predicated upon significant improvements in gas mileage (as so many are these days), I would not count on that unless it is replacing something big and heavy.
Be SURE there is a qualified shop close by- a good one for warranty service (if any warranty is left), and good independent shop for after (because dealer pricing is remarkably high).