There's a UK outlet for Artist guitars https://www.artistguitars.co.uk/, so I've just ordered a 4 pack of their 10s to see what they're like at £12.95 including postage. A lot cheaper per set to get the 12 pack, but I need to know if they're worth using first. Even if they turn out to be not that great for me, I get through a lot of strings in setting up my guitars, so could be very useful for that as they are the same gauges as my D'Addarios.
I really need to get some Harley Benton string sets to try as well (from Thomann) as they are even cheaper £1.33 a set - but no multi packs. Need to get a last order in from them before the end of the year when anything from Europe is likely to cost a lot lot more and also incur a customs processing charge. I know from friends that these strings don't last as long, but if you were gigging regularly and change strings every couple of gigs, then that doesn't really matter.