All built at the same park, which happens to be one of the most popular traditional amusement parks in the world.. not exactly the best example..
Behemoth cost 20 million.. in Canadian, but its at a park which gets nearly the same attendance as Cedar Point.. the investment was due. I'm pretty sure Fahrenheit and Max RPM aren't over $15 Million.
Lets not even touch Disney, as 1) They aren't into huge rides such as MF, and 2) The money supply they have is from another world.. no regular amusement park is even close.
Other then that, aside from a few bigger B&M's and experimental rides, you typically don't see coasters over $15 Million USD built anymore. All of the major parks which have the ability to get one of these mega giant expensive coasters have done so.. so investing in another.. as essentially the Coaster Wars are over.. would be a mistake, as you see with Cedar Point's investment into Maverick.
Size and speed are really a thing of the past in the Amusement Industry IMO.. which is evident in the recent investments within the industry. If you see anything over 275ft or $20 Million in the next 10 years, I'd be incredibly surprised.