I think Kobo is giving the publishers bad advice in this case.
While I understand the short term logic of it: when the paperback edition sells for $7.99 in the USA and $25 in New Zealand, and overseas sources such as Amazon are charging far more for postage than the price of the paper book, then there is room to increase the ebook price and still have it look cheap in comparison to paper.
But I think it generates resentment in readers once they have got past the initial comparison with paper and start comparing ebook prices in other countries, and that will hurt the publisher in the long run.
My advice to publishers would be to set a single global price, just allowing for different tax rates and a small buffer for currency shifts. (Edit: And other local factors, but be fair and use the same method for all countries rather than singling out some for special treatment. See reply to GERGE in
post #13)
(Edit: I'm not saying that it is always a bad idea to increase ebook prices, in some cases I think publishers really are setting their price too low, but be fair about it and increase the price everywhere not just in certain countries.)