For the '08, 18000 sounds like a lot, but it is a 6 year old bike. Which works out to 3000 a year, or 250 miles a month (being in Austin, I'm presuming a long riding season), not that much riding at all.
I would be more concerned on the maintenance history during those six years and what has been done, or more importantly, what hasn't been done.
The aftermarket fairings/paint scheme do make me a touch suspicious as most folks only change those when damage has been done - as already mentioned. Though there is the possibility the owner hated the stock scheme and just got a new design for the heck of it.
I do second the general opinion that the price is high for the age of the bike. Keep looking, get a ballpark price of your area, and if you are sold on this bike as the One, take your buddy and your knowledge and talk the owner down.
BTW, preachy moment, if you have never ridden before and only your buddy is teaching you how, unless he is an instructor, i *strongly* recommend taking a formal training course. Classes can show you all the basics, the proper way to ride, and give you a skill set that you can build from. Friends teaching have all the right intentions, but can easily miss things, or show improper techniques built from how they learned. /preachy