'colossal cost' is correct and usable in written English.
It is used to refer to something that is extremely expensive or very costly. Example sentence: We didn't expect the project to involve such a colossal cost.
She dismisses worries about the colossal cost of protectionism or of debt-servicing with a devalued currency as scaremongering.
It takes no account of the colossal cost in energy and carbon of destroying so much existing fabric and building it again.
"Ironically, his greatest achievement was the one of which he was later most ashamed, and that was to get Concorde going at a colossal cost, very much higher than originally imagined.
The truth is that Labour's pre-crisis budget deficit of £39bn, or 2.7% of GDP, was dwarfed by the colossal cost of saving Britain's failing banks which by 2009 was equivalent to 90% of GDP.
The truth is Labour's budget deficit then of £39bn or 2.7% of GDP was dwarfed by the colossal cost of saving Britain's failing banks, which by 2009 was equivalent to some 90% of GDP.
The colossal cost - £6bn and rising - caused one defence chief to characterise the vessels to me as "financial Death Stars".
The problem is this: these colossal increases have colossal costs.
The same was largely true of the colossal costs of post-1989 reunification.
He talked about other damaging aspects of Suárez's legacy — most of all, the way the regional nationalism of Catalonia and the Basque country were addressed with "artificial constructs" that "burdened Spain with colossal costs and endless opportunities for corruption".
The Hinkley project has been criticised for "colossal" costs by the French energy minister, who suggested it should be delayed by several years, and EDF's finance director resigned over the issue, but president François Hollande has fully backed the project.
(The colossal costs of this ambition would be imposed in rising scale over the next four decades on many folks who are now not yet old enough to vote).
