Sometimes I browse sites Cars.com to see what some people want for their cars and what kind of shape they are in for curiosity. Also I look at how much the seller wants and at times of the prices they are asking. Here are a few I found that are active as of yet. I will post the links and saved screenshots in case the car gets sold or taken down. Plus if any of you guys are in the look for a new GP I guess this thread can help too.
2005 Grand Prix GTP with 40K miles. Guy want $12K for "low miles"
2005 Grand Prix GTP with 75K miles. wants $7.5K
Although not a GTP an 2006 GT is basically a GTP. Guy had major work done to transmission and the car has 140K miles. But he is asking close to $9K do to this "work" done.