google 30,000 mile Subaru service, there's like 10 thousand hits. looks like $400-$500 is what they're hoping to make for that service.
best bet is to listen to people that know what they're talking about and don't stand to make money off of you. and then ask them specific questions if you're worried or concerned about something specific.
you should also glance or compare to your OWNERS MANUAL it has all the maintenance intervals in it and should have come with your car.
here's Subaru's official maintenance schedules for 2009 (which will look similar to yours):
it only mentions to inspect gear oils, not replace them.
the dealer service packages are terrible economic decisions - they are very much marketing based. i can explain further if you'd like, but the "sales" department of a dealership does not stop at the showroom floor. they can predict, logistically analyze, and market towards what people are willing to pay over the life span of a car, certain mileage points, etc. dealership profits are completely different than they were just a short time ago. they don't make money on cars - they make money on services now, a huge industry shift has happened since the 80's.
they're still providing a good service and all so they're not "wrong" or "of the devil" but they're certainly not good financial decisions and have no advantages over a proper maintenance schedule. the service managers are trained to sell like a salesman, some aren't even that mechanically inclined (but many are) and need to ask the mechanics specific questions.