A little help with some advertised motorcycles in the DFW area

[RainMaker]

Do any of you have any knowledge of these motorcycles or the owners?  Just taking a shot in the dark.

2006 Kawasaki ninja zx6r 636 - $5500 (Dallas, Tx)
http://dallas.craigslist.org/dal/mcy/4389446811.html

2007 blue Ninja 650R. Runs great! - $2900 (Fort Worth)
http://dallas.craigslist.org/ftw/mcy/4387093882.html

2012 Kawasaki Ninja 650 in MINT condition with only 350 miles - $6500
(North Fort Worth)
http://dallas.craigslist.org/ftw/mcy/4370553251.html

2009 Ninja 250r WTS/WTT - $3000 (Plano)
http://dallas.craigslist.org/dal/mcy/4398049161.html

2012 Kawasaki Ninja 250R - $3600 (North DFW)
http://dallas.craigslist.org/ndf/mcy/4341324360.html

Yamaha FZ6R - $4000 (Ft. Worth)
http://dallas.craigslist.org/ftw/mcy/4336395011.html

2003 Ducati Monster 800s i.e. - $3700 (Dallas)
http://dallas.craigslist.org/dal/mcy/4336886685.html

2000 GSXR 750 Chromed Out! - $4950 (Mesquite)
http://dallas.craigslist.org/dal/mcy/4351879654.html

2001 Kawasaki Ninja - $4000 (Plano)
http://dallas.craigslist.org/dal/mcy/4383267430.html

RS TRIUMPH 2001 - $3200 (Plano)
http://dallas.craigslist.org/dal/mcy/4346481974.html

2011 Ninja 250 Special Edition - $3300
http://dallas.craigslist.org/ftw/mcy/4392273181.html

2001 Suzuki GSX-R 1000 - $5000 (DFW)
http://dallas.craigslist.org/ftw/mcy/4377984632.html

I know nothing about the ninja style bikes.  Anyone want to tell me what to look for that would be unique to them?  This is my daughter-in-law looking and of course, it's the type of bike I said I wouldn't have.  Maybe that's why she wants it!

RainMaker

[john]

     ninja  250 has a 15,000 rpm redline         ???