Just bought my Dodge used in August (forgot to add 97 in my sig) it had 123K miles on it when I got it and I'm the third owner. Second owner bought it when it was just a year old and he had had it ever since. Well about 3 or 4 months ago I noticed a popping and started having it checked out. I was told it was my trac bar but it wasn't "that bad" so let it get worse before I replaced it because it wasn't cheap. Well now 3 or 4 months later its worse I need to replace it but its gonna cost me $180 (getting a second quote tomorrow). So my experience with them so far is after 100K or so of hard use you should expect to replace them.
That is a good price if its factory, I thought they cost around $300, unless its after market like a moog part. I bought the dt products trac bar with a heim joint at the top with a special bracket, its around $300 too, but its rebuildable if it wears out for about $40 fix. Its usually the ball stud that goes in them, if theres alot of offroading it will wear out faster.