Flat trim, level at the bottom and scribed to the ceiling??

The detail of the crown makes it more obvious that the ceiling is not level.

Just a thought

Agreed. Crown is not your friend here

Whoever installed the the crown did the right thing. Had it been pushed up to follow the ceiling contour the wavy line would be very visible, Scribing is usually not an option with crown molding. The scribe would, again, be very visible.

Fortunately, there is a cure for gaps..

Small gaps, 1/4" or less, should be caulked by the painter using paintable caulk.

Smooth it out then paint it. We have used this technique on up to 3/8" gaps with success, but then our painters are very good. The caulk will need to be supported with a backer for gaps over 1/4".

The caulk is flexible and expands and contracts with the wood, so it won't crack like other gap fillers.

Done properly, you won't know it's there.

Since you have not painted yet, talk to your painter about it. He she may have other ideas.

If the bap is greater than 1/2", you will need a wood filler. We generally cut the filler as close as possible, then again seal any small gap with caulk. Generally its the carpenter who cuts and installs the wood strip, and the painter who caulks it.

I would seal the entire joint between the molding and ceiling with caulk. It just looks better and keeps small critters out. Most painters will do that automatically, but ask to be sure.

I am not kidding about the small critters. We once ran into a wasp nest built by some very industrious insects on top of wall cabinets. Until that day, I did not know our demolition guys could run that fast.

I am surprised that your installer waited until after installing the crown molding to discuss ways to deal with the ceiling being out of level by 1-1/2”.

^^

Nary a floor or ceiling is perfectly level in any home.of any age.. I far prefer flat stock vs a more traditional crown on a shaker door kitchen for just this reason, as it allows a scribe to the ceiling for the trim., Drywall and flexible caulk, and paint is the best option in this case,

The quote is high, because your contractor doesn't want to be bothered.: ) and you can bet on that.

I too like the cabinets closer to the ceiling and flat trim scribed to fit

When we remodeled the Kitchen in our previous home, we also had a noticeable difference in ceiling height (somewhere around 1", IIRC). Our designer specified 3-piece molding with the center piece a flat filler. The center piece was what changed b/w sides of the Kitchen, not the decorative molding - the top and bottom pieces were not changed and, therefore, were the same throughout the Kitchen and you cannot tell there is a difference. In addition, I think the contractor's "Finish Carpenter" handled the molding since he had a greater attention to detail and knew how to make the adjustments.

Unfortunately, it is unlikely your contractor will be willing to redo the molding without a major markup, so I suspect the caulk filler & paint may be your only options here.

[The reason I described what we did is so others who may be reading this thread later may be able to use this or some form of it.]

Note that often when a contractor doesn't want to do something, they quote a ridiculously high cost to either (1) discourage you from doing it or (2) if you agree to the cost, make a a lot of money on it. (We ran into this attitude with the aforementioned remodel.)