£/gram of protein you can’t beat MyProtein, they are the largest supplier in the UK. NB other vendors offer a marginally higher percentage protein product, but you still end up paying more per gram of protein.
this is what i usually do too, wait for a 33% offer or something and buy in bulk, can usually get 10kg (2x5kg bags) for between £60 and £70 far cheaper than competitors.
last few bags ive had tho, it doesnt seem to mix as well, i always end up with big lumps in my shaker (unflavoured powder with milk)
i thought id ask on their forum if others were having the same problem but they seemed to have discontinued the forum now, the cynic in me wondered if thats partly the reason why, bad reviews?
still got a couple of bags to work through, then i think ill try one of the other cheaper brands, bulkpowders or theproteinworks, see if i get the same problem.