im planning the same thing, but almost 50K for an E46 M3 is way too much considering which cars have come out and are coming out. i figured i dont need such a new model like the 2006, i'm looking for a 2004 with low mileage, under 50,000 kilometers (im canadian). and i've seen one's selling for mid 30K. all the advertisements list M3 at around 40K+, if people were buying them, they wouldnt be listed. but there's no demand for the M3 at that price, so that means they'll be forced to sell at a lower price. that's the good thing about buying used cars. if you look more, you'll find a model with low mileage in the mid 30K, at most i would consider paying is just under 40K. i dont know how you came to consider such a high priced car. the prices in the states are so much lower than in canada it pisses me off. i'll be searching on the internet, find so many low prices, and realize they're all american. then i search canadian listings, and they're all 10k more expensive. just look on ebay to see what the competitive prices are. and once those dont sell at those high prices, the next listing will be cheaper. M3 looks more like a rugged speed machine that'll tear up the road, while 335i looks sleeker and would fit more into a futuristic sci-fi movie.
M3(manual)>335i any day.