EAN-5 on book barcode when selling internationally
Ok, so I'm a little confused on this and have read very conflicting advice in various places.
I understand that in addition to the usual ISBN barcode that I can put on my book, I also have the option to add a 5-digit EAN-5 code at the end that encodes recommended retail price data.
Personally I'd like to add one, but the problem with that EAN-5 code is that it can only encode ONE type of currency.
I live in NZ and want to get the book into some local stores, but I want my book to be as widely available as possible, including internationally. If I set up my EAN-5 code to contain the recommended retail price in NZ dollars, would that be a barrier to, say, a store in the US stocking it? Would it be better to just use the 90000 null code rather than supplying the recommended price in NZ dollars?