$2,400! Now you know why they're called 'Stealerships'.
From your description, you definitely have one, and maybe two, problems.
The easy one is the valve cover gaskets (the 'cam case'? Never heard it called that on a Subaru).
There are two valve covers on a Subaru engine - one on each side of the engine, with the spark plug wires going into them (part 18 on this diagram). The valve cover has three gaskets on each side (parts 19 and 20). These leak over time, because the rubber seals get hard. To check for a leak, look for oil on the valve cover seams; the leak follows gravity, so you'll see the oil on the seam towards the back of the engine. It's more of a problem with Subaru engines due to the 'boxer' nature of the engine; most cars have the cam covers at the top, and oil is only present when the engine is running. On a Subaru, these covers can have oil sitting on them when the engine is parked.
To fix the valve cover gaskets, you remove the bolts on each cam cover, pull the cover off, put the new gasket in place, and bolt everything back up to torque. It's less than an hour each side. Parts cost is about four hamburgers at the local store.
The other potential leak problem is the camshaft seal. These leak oil from the front of the camshaft, and it ends up behind the front cover of the engine. Look at the black plastic covers at the very front (parts 3, 4, 5, 8 and 9) - you'll see oil along the seam. Your car has four camshaft seals, because it's a DOHC engine. They are listed as part 15 on the diagram. The part is cheap - cost about the same as the fries that go with your hamburger - but to replace them you need to remove the front covers, the timing chain, tensioners... lots of work. It takes a mechanic about 6 hours to change the camshaft seals.
I believe your car has a timing chain, and not a timing belt. If it's a chain, you can do the remove/replace with the existing chain. If it's a belt, it should have been changed at 105,000 miles as part of regular maintenance; if not, changing camshaft seals adds only about 30 minutes to a timing belt replacement on the Subaru.
I'd recommend looking for a non-dealership Subaru specialist. Don't use a normal shop - Subarus have some odd quirks - but a shop that works on a lot of Subarus can be much more cost effective for this work. And you never know - they may tell you that you can live with the leaks for a few months while you save up for the repair.