I had a similar problem recently.. Car wouldn't start but would bump start no problem. Sounds like your starter but could also maybe be your clutch switch.
Did the starter ever make any odd noise? Slow cranking? At all? Seems odd that it would have just flat out died
Have a read through this:
http://www.e90post.com/forums/showthread.php?t=925280
Starter is pretty easy to do yourself and you can clean your intake ports & valves at the same time, makes a world of difference