No Air Conditioner!

We found out today that we are going to have to get a new car, eventually. The air conditioner hasn't been working. Today, we were told that it would cost $900 (just for a new compressor) to fix our air conditioner in the Jeep. This doesn't include labor or taxes. So, that would drive it up to about $1200. In it's current condition, with 140,000 miles on it, it's only worth about $4000. Why would we put that much money into such an old car?
So, for the meantime, we've decided to sweat it out and wait to get a new car until Mark gets his bonus in the Spring. The compressor won't impact the car's ability to heat, so there won't be problems when the baby comes.
I really want a new Jeep. This is the first major problem that I've had with this Jeep, which was purchased (by my mom) in 2001. For 8 years and 140k miles, there have been no issues (aside from replaced tires and a replaced battery). It's been a great car and I've really enjoyed it.
We will definitely get a 4wd since we live on a very steep hill. If we don't get a 4wd, we won't be able to get the car up the road if it ices.