94 s10 blazer balljoint question

After trying to figure out my popping front end noise. The garage says it is the front left lower balljoint. says there is 1/4 inch play (the torsion bar mounts were replaced last year) Price to change balljoint w/ labor about 200 bucks(does not include alignment). I asked him about replacing the upper at the same time. He said not neccesssary.

1. Should i have it done anyways since he is in there?
2. If i do have it done should it cost just a little more for the part and labor or am i looking at 400 bucks 200lower/200 higher? and is 200 a going rate?

thanks mike