This is a pretty easy project. If you are willing to do it yourself, and don't run into any problems, it shouldn't take more than 1 hour per side. You shouldn't need to change the alignment. I wouldn't disconnect the strut. All you need to do is take off the axle nut and drop the ball joint. Then removal and installation is a breeze. Getting the drift pin in can sometimes be a pain. If you are willing to spend a little extra cash and get a good product, go with
www.raxles.com
They are about 150/side, but are very high quality.
The Subaru replacement will be far more expensive. I don't think they would charge more than 2 hours labor per side.