Happy birthday!
Someone already asked the key question. Do you have or are you willing to get a wifi-enabled router attached to your internet connection?
Assuming that the answer is yes, and that you will be using your Kindle solely or mostly while at home, you might actually *prefer* wi-fi to 3g.
That's what happened to me. My original Kindle was 3g, but my K3 is wi-fi and it works a *lot* better for me because I have a very weak (sometimes nonexistent) cell signal at my house.