I just paid under $19K for a 2005 SR5 V8 4x4 with sunroof and a few extras like leather steering wheel, leather on shift knob, dimming mirror, etc. It was a one owner trade in awesome condition and has 65,000 miles. This was at a dealership and they are usually a couple grand over private party. I think 17,200 is a bit steep for a V6 2wd. Is that asking price? If so, offer them $15 and start to look uncomfortable and wishy washy past that. Hold to $15,500 and be ready to walk away and tell them you will go look at another one and think about it.
This is assuming you are buying from a dealership. Private party? Just make a similar offer to start.
Get under the vehicle and look for rust on frame and exhaust, along with the other stuff- get well under there or ask them to lift the vehicle. Also look for leaking shocks and hydro lines if it has XREAS. Both Sports I looked at were leaking (XREAS lines) under 65K. Check the CV boots for leaks as well.