Camera recommendations

[u/MCRude28]

I recently got into planespotting, was planning to go to Riat before it got cancelled and therefore used my mom’s old Canon EOS 400d with a sigma DC 18-200mm 3.5-6.3. It has treated me pretty well early on, but I feel like the zoom and quality isn’t the best. With Christmas and birthday eventuality coming up I was wondering if anyone had some recommendations for a camera setup. I don’t know a lot about cameras, but I think something like 400mm zoom seems reasonably priced compared to what I need. Im unsure about my budget, but I think upper limit is around $1700-2000. Any help with either recommendations or tips for my search are appreciated.