The phrase "a very significant amount of" is correct and usable in written English.
It can be used when discussing a large quantity or degree of something, often in contexts involving data, resources, or impact.
Example: "The study revealed that there was a very significant amount of evidence supporting the hypothesis."
Alternatives: "a considerable amount of" or "a substantial amount of".
"It was a very significant amount of money that was saved," Mr. Diliberto said.
And finally, it will save a very significant amount of money for taxpayers, and for users".
We have dedicated a very significant amount of our intelligence resources to North -- the issue of North Korea.
A very significant amount of wind energy is contained in the movements of air at high altitudes.
By that time he had already made a very significant amount of money (frankly, I am not sure how Mr X did this).
Grayling said the organisation had raised "a very significant" amount of money, thought to be more than £5m, to fund the college.
In November the European parliament's Brexit coordinator, Guy Verhofstadt, warned the UK's Brexit secretary, David Davis, that a family of five could face a bill of £360 – "a very significant amount for a family on low income" – under the UK government's planned application fees for settled status.
But, of all the Polanski ironies, the greatest one of all is the sheer audacity, the outrageousness, the tone-deafness, and the stunning arrogance of offering a "very, very significant" amount of cash for release, after the court has expressly denied bail.
Even more chilling is the potential impact on our leading scientific institutions, the Royal Society and the Academy of Medical Sciences, both of which receive very significant amount of their funding from government.
Tiny particles known as micrometeoroids will strike whatever they encounter in space, causing potentially very significant amounts of damage as a result, especially as the collisions build up over time and occur at higher speeds.
