The phrase "astronomical amount" is correct and commonly used in written English.
It is typically used to describe a very large or immense quantity of something. Example: The cost of the new space program is expected to reach an astronomical amount, with estimates in the billions of dollars.
The cornerstone was laid in 1923 and the place was built for $750,000, an astronomical amount at the time.
"They'll have to clean from the bottom up, an enormous job that will take many years and cost an astronomical amount of money".
No one in the building could believe that I would pay so much in key money for a rental apartment; it was an astronomical amount.
I don't remember the exact fee for joining, but it was several hundred dollars — an astronomical amount for the early 1980s.
EBay helps buyers find that very odd, one-of-a-kind part in a way that doesn't cost an astronomical amount".
She said all nonresidents, whether guests of residents or not, paid the same $5. "I had some people recommend charging an astronomical amount.
I have seen the salaries grow to astronomical amounts.
Not only does it involve astronomical amounts of money, it also operates with alarming secrecy.
Early this year, several domain names sold for astronomical amounts -- www.business.com for $7.5 million, www.loan.com for $3 million and www.beauty.com for $1 million.
This was logical on both sides, writes Ian O'Connor on ESPN.com, mostly because the offseason never really starts until the Yankees start tossing around astronomical amounts of money.
And the reason that chief executives didn't pay themselves the astronomical amounts they later did was precisely because of the bad example it set in terms of the next round of collective bargaining.
