$700.00 is way too much. typical dealer price.
belt tensioner has several parts and can be replaced
individually. i had mine recently repaired. my mechanic
replaced the rod and the adjuster. parts and labor cost
is $200.00 canadian dollars. labor ate up half the cost.

and yes your a/c will be affected by a defective belt
tensioner. my a/c compressor used to cut out before the belt tensioner was repaired. thanks to the advice of Steve B. of this forum, problem solved.

[Edited by joel on 06-23-2001 at 09:10 PM]