At least in the UK the retail export scheme only applies to people who either aren't resident in the EU or in some cases is ending temporary residence AND who buy the goods in person (not mail order). It also only works if the retailer is part of the scheme.
I'm not sure what the situation is in ireland, I couldnt find any explicit prohibition on mail order when I looked for Ireland but I may have missed something. Even if there is no such provision I doubt amazon UK would participate in the Irish version of the retail export scheme.
If you are eligable for the retail export scheme I guess it may be possible to have a Buisness in Ireland buy the goods from amazon (which will give them the ability to either reclaim the VAT or not pay it in the first place) and then sell them on to you in person (which would allow the retail export scheme to be used) but I would expect the cost of setting up such an arrangement to eat up much or all of the savings.