Which Pixel Phone for Kraken?

[Mark424]

I just got a Kraken phone housing. My daily phone is a pixel 3XL, but like others, I am a little worried about trashing my phone when I'm traveling out of the country, so am thinking about picking up a used/refurbished phone to just use for scuba photography.

My question: Are there substantial differences in the cameras in Pixel 3/3XL, 4, and Pixel 5 for scuba? Obviously the newer ones are much more expensive. Any reason to splurge for the Pixel 4 or 5 over a used Pixel 3XL?

Thanks

Mark