you could keep it cheap & cheerful and get a caravan, a fraction of the price (even if got a new one which are very comfy), also get mobililty around Ireland, foreign travel option.
Especially if you've room to leave it somewhere, either at your own home or somewhere down the country, then should work out a lot cheaper on annual costs.
With the awnings (side tents you can attach) you end up with a lot of accomodation.
Better bang for your buck imho. While a mobile would be more comfortable in off peak seasons, I gather a lot of the parks where you'd leave a mobile arent open then either. Sure have a look at one or two newish caravans before you finalise on a mobile.