As someone who now lives in the UK (have done for about 5 years) the reality is that Transport, Taxi, Food, Dining, Drink, Shopping, Attraction prices are a lot more than comparable prices in the UK. The perception in the UK is that "Ireland is great, but soo expensive" in the same way Scandinavia is thought of as expensive. The other problem is there is a distinct lack of mid-range options on the streets and in cafe's, etc. There is either the super-cheap fast food, or fairly pricy dining, very little affordable casual dining. Even Milano would be a fair bit more than the identical Pizza Express in the UK.
This does turn people off. In fairness prices have become a lot more realistic in the past 12 months, but there is still a long way to go to be competitive and change the perceptions.