The phrase "a substantial sum to" is correct and usable in written English.
It can be used when referring to a significant amount of money that is being allocated, given, or required for a specific purpose.
Example: "The company decided to allocate a substantial sum to the new marketing campaign to boost sales."
Alternatives: "a considerable amount to" or "a significant amount to".
The Australian entertainer has been paid a substantial sum to spruik Rupert Murdoch's Australian newspapers.
All of this assumes that you have a substantial sum to save.
Nine has also denied paying a substantial sum to the children's Lebanese father in return for dismissing the kidnapping charges.
The Daily Telegraph had refused to publish the story even after it paid a substantial sum to secure the exclusive rights.
Sources close to the investigating team say the main supergrass volunteered key information about the killing, saying he had been offered a substantial sum to kill Morgan.
His care and affection were illustrated by his bequest of a substantial sum to finance free Boston Symphony tickets for Harvard undergraduates.
Caramell was bought from Sweden for a substantial sum at the end of last year to help Malhas's Olympic bid, but an injury to its back was diagnosed six weeks ago and it will not have recovered in time for the Games.
In 1799, 58 gentlemen including Sir Joseph Banks, Count Rumford and Henry Cavendish invested 50 guineas each (a very substantial sum) to establish an institution that would introduce new technologies, diffuse knowledge and apply science to the "common purposes of life".
Extra payments can include adding just a bit more than your current payment or adding a more substantial sum to your scheduled monthly payments.
Two months ago, he spent an undisclosed but "very substantial" sum to bulldoze the 1,000 square foot convenience store next to one of his stations and build a 4,200 square foot grab-and-go food store with a coffee bar and three extra staffers.
It is understood the BBC offered her a substantial sum, believed to be between £75,000 and £100,000, not to take the case to the tribunal.
