What are the wattage of the lamps? Are they LED or older Halogen bulbs? Quality LED down- light lamps are £ 20 per fitting trade price. Around 4-6 Watts per lamp
But it's a rabbit hole to go down, we have 12 in our kitchen/dining area 2 banks of 6. but as 6 of them are in the kitchen they have (or should) be at least IP44 (I think) or better still IP65 so the cheap ones are £7.48 from Screwfix, £90 in total, these are also round our existing ones are square, ceiling will then need decorating, that is assuming that the holes of the existing ones are 72mm like these. Then there's the hassle of fitting them & then the big one, how long is the ROI & is it worth it.
12x 30w & each bank is on for less than an hour a day I would think, were they highly used I would agreeROI is quite short as you'd be using approximately 1/10th of the elcetricity.
12 x 50w watt downlight is using alot of £ over a year at current prices.
What are the wattage of the lamps? Are they LED or older Halogen bulbs? Quality LED down- light lamps are £ 20 per fitting trade price. Around 4-6 Watts per lamp