[TSM330i]

Congrats on the family addition!

My wife and I have one kid also. Do yourself a favor and get the biggest vehicle you can within your budget. My wife went from an e90 sedan to a 2012 X3. The added space is MUCH appreciated, not only for the kid, but for others that ride in the car. My wife sits in the back when I drive and the leg room with our X3 is stellar. She sits behind me (I'm 6'1") and she has plenty of leg room to be comfortable. There is ample room in the back to haul quite a bit of stuff as well. If you have a dog too, you'll want as much space as you can get.
We can also fit my in-laws in the X3 with us (including a full-blown Recaro child seat - my little one is 2-1/2 years old now. My in-laws are not small either. My wife is in good shape, so that does help.
Bottom line, get the biggest vehicle you can. It'll definitely pay off in the long run.

That being said, if I were you, I'd look at a Subaru. They have a great line-up and the price is right in where you want to be. The Forester has about as much room as the X3 and quite a bit more rear legroom than an X1. If you increase your budget to about $28K (actual price, not MSRP), you can get an XT Premium with the 250hp turbo engine.