Cheap Christmas Decorations?

Dollar Stores and there are many! also big box stores like Big Lots etc.

If you have a B&Q near you, worth a look for artificial trees... I saw over the last week very reasonably priced 4-6 foot trees near the €30 mark to €64 as I was comparing it to the artificial tree in Lidl (€30, 180cm in height, 110cm in width) that was on offer for someone else. Tesco and Argos also do artificial trees, usually (from what I can remember from house shares) near enough on a similar price.

For decorations, it depends what you want. Pound shops can have some nice buys depending on your budget, I was in Home Store + More during the week having a look (again, for someone else I thought needed it) and they had a mixed range including stock similar to what you would see in pound shops like eurogiant and dealz.

Tesco have some decent enough bauble sets, some stuff that is sold individually is really nice and cute. Dunnes, Pennys, M&S, Arnotts, Heatons, BT all probably have their own offerings along with most other department stores and various supermarkets.

Lidl (and most likely) Aldi have had various decorations of baubles and gap filler stuff, room decorations. Lidl definitely has had lights.

B&Q, Woodies, they'd all have decorations, incl lights but some (not all) garden centres would also have seasonal shops that include Christmas decorations or would include for it in their general shop if they also sell home furnishings and giftware.

tbh if you just want cheap and cheerful and aren't too fussed about quality or having something last, there's plenty between pound shops and supermarkets on offer.