A while i was looking at getting a Kobo Libra 2 because it seemed alright. I ended up getting a used Sony PRS-505 instead, because it also does everything i need and was slightly cheaper. The battery is fine for how old it is, my only complaint is that some really big books (A Complete Guide to Heraldry, The World's Writing Systems) crash it.
Do you need a built-in bookstore? Compatibility with your local public library? Physical buttons? I think those are the main things to watch out for besides price.
Do consider buying used if that's practical to do.