Only 2 things really interest me - long battery life & cost - sub £250 ~= US $ 350, Eur 290 .
I am replacing an old UleFone Power which had an 1100maH battery (!). I don't care that it was a brick - I loved it.
I use my 'phone for Email, WhatsApp, SMS and occasional 'phone calls & to browse, generally to read the news.
I *never* play games, stream videos, use any social networks, listen to music, etc. And I don't care too much about camera quality.
A reasonable amount of memory would be nice (NFC would be a bonus, but I don't expect it).
I have no problems with non-mainstream brands. What can you recommend?