I just turned 19 this october 15th, and for my bday my rents got me a 325i monaco/beige automatic base model. I could not be more happy with this car.
At first i tried to convince my dad to get me a 330i, but after a few days i just decided that it was good enough to be getting a bmw, no matter what kind it was. A few weeks into owning the car, i can say without a doubt i made the right choice. The 325 cost over 120 dollars less per month, costs less on the insurance, and also not to mention the dealer gave my rents a very very good deal since they had leased an x5 from the same dealership a few years ago. This car turned out to be a bargain...399/mo 0 down...turning into 430 a month with taxes and a few other minor payments included in the monthly payments.
I think you should just be happy with the 325. Its a hell of a lot of car at such a young age i think.
My first car was a 2003 infiniti m45...a 340 hp v8 monster. I originally thought going from 340 horses to 215 was an atrocity...but after actually driving my 325 around for a few weeks, i can say without a doubt that i love this car far more than i ever liked my infiniti.
OH BTW: just so you know...i ended up totalling my M45 last month after a night of heavy drinking. So extra power on your car isnt always the best thing.