Well, I did some research for ya. At a price of 3800 Canadian it would be somewhere around 3100 American dollars (I think?), 200,000 KM=would be around 124k miles. Looking at the pics it all looks pretty solid, the interior looks especially excellent, but for the overall car I would say it is in just good condition because you mentioned a cracked grill and a thumping noise. So according to Kelley Blue Book, one in good condition is worth around 3700 American dollars, one in fair condition worth around 3150 American, but what condition the car is actually in is for you to decide since you're the only one who's seen it in person. Either way I'd say you'd be getting a pretty good deal, since with proper maintenance that car will last you a long, long time. Just make sure you get that thumping problem addressed if you end up getting the car. The engine swap idea, as previously mentioned, is going to cost quite a bit, and if you are looking for a faster, more powerful car, you might want to consider looking for something with a 6 cylinder, such as a 325 or 328. That being said, the car can still be quick with the current motor, a buddy of mine has one of the hatchback 318's with a 4 banger in it and that thing is zippy as hell. It really doesn't matter what BMW you choose to buy, they're all great cars and I can almost guarantee you'll love whichever one you end up buying. My advice: take the thing for a test drive, see how it drives. Hope all that helps