My BMW 330i sedan is cheaper to insure than my Honda Civic. So insurance is a wash. The lease deal would be good if you had no down payments but considering you are putting $5,000 down, you could do much better. Check out e90post.com for more info but there are people who got similar monthly lease payments with no down.
Also, sport package is a MUST. You get sport seats, sport suspension, sport steering wheel, and the speed limiter raised from 135 to 155mph. You can replace the steering wheel but you cannot replace the seats, suspension or limiter without substantial cost.