That was exactly the case with me. My insurance only covered 1/3 of the costs. I did go to Mexico and saved a ton. It was 11K for a full, virgin DS. I went to Dr. Esquerra at Mexicali Bariatric. We have lot of his patients here.
I got great care and more attention from the Drs than I would have gotten in the US. I had 3 Drs stop by twice a day for three days and the nursing was fine. Pain management was fine. It was a very smooth process.
I thought I was crazy when I first thought about Mexico, but the more I researched it, the more I felt comfortable with it. For a DS, Dr. Esquerra is vetted. There is another Dr that is vetted and you can find on the DS facebook group, but I did not take that route.
I do think it's very important to line up a good primary care doctor for once you surgery is done. It took me a few weeks to find the right Doctor. But the fact my PCP knows about the DS made me much more comfortable with Mexico. I also think it helps to have a local in person group to go to.
It's not crazy to go to Mexico, you just need to do some extra research and have follow up care lined up.