This math is what lead me to the iUp program in the first place. It's effectively a guaranteed 50% trade-in, which came out to about $200-300 in actual money that I was theoretically sacrificing in exchange for not having to worry about the cosmetic condition of the phone or weirdos on ebay.
And it came with AppleCare+ with Theft and Loss. I stopped using a case. I lived free.
I’ll never stop using a case. Too clumsy, too careless. 2-3 days without my phone would be manageable but why?