Costa coffee and rip-off Ireland

I always thought Costa's Irish price of 5.99 euro for a pack of their house-blend coffee was a bit steep, but I didn't realise how steep it was until I visited Costa in Brighton, where exactly the same product retails for 3.24 euro (£2.99). The Irish price is almost double the UK one. Rip-off Ireland strikes again. What is wrong with this damn country?!?