I think their original price was $500.
For decades, Kirkus had the reputation of being a respected journal that libraries used in deciding what trade books to buy. Their reviews were excellent. Today? I couldn't tell you if the claim that agents and industry pros peruse the paid-for reviews on the Kirkus website. I'm guessing they don't.
The advantage of buying a Kirkus review--if it were to be positive--would be that you could use much or all of it in the Editorial Reviews section of your book's metadata on Amazon and on other publicity for your book. It's possible a positive Kirkus review would help influence getting a BookBub featured deal, or in getting picked up by Publishers Weekly for a review (although you can pay for theirs, too, but not in the PW mag, only in Booklife). The interesting thing about the Kirkus reviews is you can suppress negative ones.
TBH, I wouldn't waste that kind of money on a review. Much better to spend it on a content edit, or as a down payment on one, more likely.