Q: Is it true that the last digit's on BMW's tell you how much the car cost's ex. 330i is $30,000
A: No it is not true. The first number is the series of car, in this example the three series. The last two digits used to give a clue as to the size of the engine. But this is no longer the case. For example a 328i has a 3.0 liter engine, but so does the 335i. The second one just has a twin turbo on the same size of engine. The last letter means something too. You can probably get a list from some enthusiast web site. Another thing to keep in mind with BMW is how much you can customize them. In fact BMW claim that there are over 130,000,000 possible configurations of their vehicles. So with that in mind there is a lot of price variance. If you take a three series as you did in your example, the current base price for a 328i is $32,700. But if you order it with most of the available options you can easily push the price to $50,000. The new one series 135i costs $36,275 but if you load it up with options you can be close to $48,000 for the same car. With such a wide range of options and price differences, it wouldn't make much sense to use the model number as a price indicator.