Four wheel drive is been taken off

I bought my daughter a used car. Right before we signed papers he told me the four wheel drive did not work. He said it was not a big deal and stupidly I believed him. I drove the car and it ran great. Just when I turned it to the left it felt like it was pulling. She took it to the mechanic after we bought it and he said it needs to be replaced and something was broken. Something inside the driveshaft or gear shaft. And it would be $3,000.00 to fix and get back the four wheel drive. As her mom I am worried is the car safer for her to drive? And does it really cost that much to fix? The car only cost $3,800.00. That is what we had, if I had an extra three grand. We would have been looking at different cars, lol. Any advice would be appreciated.