Don't forget that generally batteries are weighty and their weight affects postage costs particularly from overseas.
Not uncommon, at least for Australia, that the post for a battery equals its cost, whereas some suppliers wont post at all.
Have also noticed that a lot of suppliers have stopped offering alternative delivery methods and only use "official" air mail service, supposedly because the item can be tracked.
This makes buying their products cost prohibitive no matter how good/suitable they are.

Another example cast metal fittings.