Re: Band bingo
"Phones with global LTE coverage already cost a fortune. "
Unless you mean you want something that works with both CDMA and GSM I don't think you're right.
Early 4g phones were quite expensive but a lot cheaper than a new iPhone. Many Far Eastern phones have "global" editions which cover all the usual bands. I paid £240 for mine.
I expect 5g to get to reasonable prices about the time I need a replacement.
Biting the hand that feeds IT
