It turned out the brake piston which was leaking was just seeping. I'll have to keep an eye on it and my brake fluid levels, but it is drivable for now. The entire caliper doesn't need replacement, just one portion of it. So it shouldn't be too horribly expensive, and it's not really all that hard a part to replace.
HOWEVER, my shocks were also starting to give out (I thought the back end of the car looked like it was starting to sag). I decided to go with some stronger coil-overs, which were a bit more expensive.
I was expecting to blow my entire paycheck on this, but it ended up only costing half. :P