Are you going to install it yourself? Good way to save money.
I put the following in my car about 4 years ago:
1. JVC Exad touchscreen headunit - $500
2. Focal splits - $300
The car already had the following in it:
1. Rear Pioneer 6 inch speakers
2. Pioneer 10 inch free air sub
3. Alpine V12 4 channel amp - 2 channels briged for the sub, the other 2 for the splits
4. Pioneer 2 channel amp for the rear speakers
In my previous car I put the following (about 7 years ago):
1. Sony head unit - $300
2. Pioneer splits - $250
3. Alpine 4 channel amp - $300 on special, was an awesome buy
4. Kenwood 7 x 10's in the rear ($250?)
It was pretty simple but sounded decent. I didn't want to go for a sub so I went for 7 x 10's. Not the most refined but effective. I got away with it for less than $1200 all up.