A 5 month wait for a 325 or 335 coupe is ridiculious and I wouldn't stand for it. There are a lot of cars out there for that sort of money which are just as good and arguably just a stunning. I don't doubt they have plenty of orders for them but I also think BMW are limiting the numbers coming in so they keep the value up. I'm sure if you got them on paper for a deal and said your signature would go on if the delivery was confirmed for no more than 3 months, they would make it happen.
As for the $200K M3 - The only people that would please would be current E46 M3 owners as their cars value would not plumet too much with the new M3 release.