Using the standard exchange rate between U.S. dollars and British pounds won't give us an accurate prediction of the American price, so instead we can use a number of calculations to come up with an estimate.
First, we'll compare the U.K. and U.S. pricing on the new 335i convertible, whose pricing was announce just earlier this year.
The 335i Cabrio is £37,895 in Britain and $49,100 in America. That's a conversion rate of plus 30 percent. If BMW uses the same exchange rate for the new M3, it would cost $65,800 in the United States.
We can also look at the price of another BMW "M" car and compare conversion rates. The BMW M6 is advertised at $99,100 in America, and £82,605 in Britain. This leaves us with a conversion of plus 20 percent and an MSRP of $60,700.
Next, we'll compare pricing of the M3's nearest rival, the Audi RS4. In Britain, its base price is £50,930. In America, it sells for $66,000. That's a conversion of plus 18 percent, which would make the M3 cost just $59,740. However, another automaker's pricing is not particularly useful in this way. On the other hand, it's worth pointing out that the RS4's U.K. price is nearly identical to the the M3's U.K. price. Does that mean the U.S. prices will also be identical? If so, our $65,800 estimate still sounds reasonable.
Lastly we can compare the percentage increase from the old M3's price to the new one. In Britain, the old M3 cost £42,450. That means the new price is an increase of 20 percent. Again, we're back to $60,700.
While we can't draw any firm conclusions, it's safe bet the new M3 will cost between $60,000 and $65,000 in the United States -- a significant increase over the old M3's $48,900 price tag.