Technology Outlet is doing a clearance on a range of 1.75mm and 3mm filaments due to left over warehouse stock. Check it here: https://technologyoutlet.co.uk/collections/clearance/products/clearance?variant=32393802285135
Additionally, they're also doing 33% off on PLA Premium, so it will cost £19.98 instead of £30 (in case you can't grab one from the clearance section): https://technologyoutlet.co.uk/products/premium-pla-plus-3d-printer-filament?_pos=1&_sid=8104a0e5a&_ss=r