What is the approximate cost of having the transmission replaced on a 1999 ford taurus?

I just got my tax refund (yay!) and my dad is giving me our ford taurus as a hand-me-down but in order for me to drive it, I am in desperate need of a transmission replacement. The car turns on, but doesn't shift out of neutral or park so, as you can imagine, in order to move it we have to push it haha! I was just wondering about how much is it going to cost. I would imagine hundreds of dollars but I was hoping I had enough to get it fixed and on the road!