I brought a second hand car in from the UK recently. More hassle and either you or someone else needs to know a bit about cars but excellent value even when you factor in VRT, flight, ferry etc. I even got a warranty that's effective over here. I think in NI the cross border factor is priced in so cars aren't as good value.
PCP is very expensive. You're paying a high premium for certainty in regards anything going wrong and of course the removal of hassle of resale or getting done on a trade in.