I bought a 2009 4Runner back in March for $15k. Back then $15k would buy you the nicest 4th Generation (03-09) 4Runner. Now days that seems to be the average asking price, most 4Runners from that generation are going for at least $12k (with over 200k miles) and the nicest ones (with low 100k miles) are fetching over $20k.
That's 15k to 20k for a car that is 11 years old at it's youngest and mileage under 150k is considered "low mileage"