In terms of cost, the NIR packs work out at €66.66 a coach, in a three pack, the Orange 4-packs are €67.50 a coach, and the Park Royals are individually €69.99 each. The MM Mk2d's are €59.99 each, but do not have on board lighting, or close coupling systems, etc. So it's all pretty much on par tbh.
Also we're down to just 6 versions still in stock - should we get more?
https://irishrailwaymodels.com/collections/murphy-models-mark-2d-coaches/availability_in-stock