That fuel mileage is about right. I've owned a few of those. The auto V6 4 Runners of that era are very underpowered IMO. The V6s are also one of the most problematic engines Toyota has ever built (google it). If it were me, I'd try to find a 4 cyl 5 speed. Similar in the power department to the V6 auto, a little better fuel economy, and much better reliability.
I had a 93 4 Runner that got 16mpg highway, 13 mpg city, and 11mpg towing. It had a poor rear suspension for towing and needed rear spring bags to lift it. Even not towing, it was not uncommon to see sagging runner-butts. This series of engines had a major recall on the head gasket, such that if not replaced, would leak coolant into the combustion chambers and valves. Mine fortunately got replaced before damage. The resale value on a 100,000 mi runner 6 years ago was around $12000-16000, so expect to see higher mileage and at least a $8500 investement, not including repairs such as timing belts, pumps, hoses, radiator, brakes, tires, etc. As I sold mine, the hatch window motor shorted. Not a bad vehicle if you can put up with aging equipment. The motor was solid however, and I would have expected it to go 250,000mi until a rebuild.