FYI, you may want to look at these guys:
https://zanottiarmor.com/
They make safes that can be broken down into six pieces or so for easy transportability. The safes are manufactured in jigs so that they go back together with pins the same way every time. They are pretty high quality and earned a place in the industry. They will provide better security than any of the cheap Chinese-built safes from the box stores. They don't provide any insulation for fire protection. They only use combination locks to stop a lot of the problems with lockouts from the digital-type locks. They are always in demand and lead times can be 14 weeks unless you buy a safe that somebody cancelled on. In my opinion, for your budget and requirements, they are a way better option than the other products you are looking at.