I've been through urinary tract obstruction woes with one cat. $1800 sounds steep, even if it includes emergency care.
If you do have the surgery performed (and yes, the cat will die if the obstruction stays in place--I lost one to this problem 35 years ago before much could be done for them) YOU MUST change the cat's diet.
Elsewhere, I have ranted about the dire effect dry food can have in inducing diabetes, but dry food also is a bad idea with a cat inclined to plug (and once they plug, forever after you must watch them for signs of straining, or bloody urine, because they are likely to plug again). Go to a low carbohydrate, canned food. Not all are wildly expensive. Cats just are not inclined to drink enough water if fed dry food.
This is my boy: