I've asked this question in many threads. And the answer is this:
There is currently no place that sells a brand new and unlocked (in every sense of the word) iPhone SE anywhere online. Trust me, I looked everywhere.
And just to be clear, pre-paid phones are NOT unlocked. Even if it is unlocked, you are basically agreeing to the terms and conditions, which state that you must have service for so long.
I always get the "yes, but this or that" answers. Again, there is no online vendor that sells a brand new unlocked iPhone SE. They are all gone. Best Buy, Walmart, Target, Apple, Amazon, etc. none of them have it. They are gone forever. Sure, you can still find a brand new one on eBay at a premium, but it's not from an authorized retailer. And most of the iPhones SE listed on eBay as "brand new" are not actually new. They are either refurbs sold as new or "open box", which isn't new.