Walk away. They may call you with a much better offer in a few days. I was just looking at an 08 with 124,000 miles. It was originally 16k, i went in and it changed to 15k, I took it for a drive, looked it over, but still walked cause i didnt really need it. I was just looking. They called back two days later and knocked another 1k off.
Walking away will likely bring you a better deal. If not there are always more out there. If the mileage was lower it might be worth that but over 100k i think the price is high. I saw another one 08 limited for 16k at a lexus dealer with 100k miles. That seemed like a decent deal but 17k seems high. Thats a 6 year old car.
Ah but i noticed you are in denver... colorado seems to be much higher priced when it comes to buying tacomas and 4runners...