1998 impreza w/possible transmission probs

[catherine mason]

i have a 1998 impreza with 66,000.
the last couple of weeks i've have the following problem:
when i make a turn from a stop, the cars response becomes very
unresponsive(sluggish).
example: when i turn onto the road from the driveway, if i don't press on
the gas pedal hard, the car becomes very unresponsive(sluggish). visual a
bike chain with some missing links and trying to pedal that bike with the
described chain.

i brought it to the garage today and was told it could be either the
transmission or differential, and it could take 3-5 days to fix.
i have to bring it to the transmission specialist for them to look at
monday.

my question is : is it normal for a suburau to have a
transmission/differential problem with only 66,000 miles????
before i had a plymouth with 124,000 and never had a
transmission/differential problem.
i thought subarus had a fairly good reputation!!

can someone tell me what the possible repair bill could be if the problem is
transmission vs differential(i'm in the ny area).

thanks for any help in advance.