I'd say go with what your wallet tells you but 512 gb storage is a sweet spot for me.
I do plan on holding on to my iPhone 14 pro max for 2-3 years and the 512 GB would be nice to have, but after thinking more, I think 256 would be fine. I had my 11 Pro Max 256 for 3 years now and only use about 88 GB ( I misspoke earlier about 90 GB).
I will probably use the phone for video and photos but I can always offload to my mac if it comes to that. Plus, I plan to buy the Apple Watch Ultra in November, so I have to stay within the budget lol.