2001 Subaru windshield wipers

I bought a used 2001 subaru outback this spring, and today the windshield wipers failed. A couple nights ago I came home in a heavy snowstorm, and I had to use my wipers to clear snow and water. Today, while I was in school it was snowing fairly heavily. When I finally got to my car, there was about 1/2 inch of snow on the windshield. I used the wipers to get it off and it worked great. I allowed the defroster to run while I cleaned the rest of the car. I then drove a couple blocks to my friends house and parked there, car running with defrosters, for about 3-4 minutes. I noticed that my drivers side wiper was not down all the way. It was up probably about 1 inch above normal down position, because there was snow under it. I cleared the snow and ice from under the wiper by hand. I got back in and drove another block, again stopping for less than a minute. This time when I tried to use the wipers, the drivers side wiper hesitated, and now it starts late. When I engage the wipers, the passengers side starts first, and by the time the drivers side goes, the passengers wiper is above it, blocking it. What happened, what can I do, and how much will it cost me? Im not sure if it means anything, but when the wipers are off, I can move the drivers side wiper along it's path by hand. Thanks guys.