£5 a kilo is £5 for 2.2lb which is about $3.50, or roughly $1.60 a pound.
Sorry but protein factory (or anyone else) CANNOT beat that.
I can personally guarantee the whey, I use it myself. It is a group buying scheme between a group of UK bodybuilders, with very little profit for the guy (Mobster) who does it.
To get it at £5 a kilo you need to buy 2X 15 kilo sacks, which when used about 3 times a day will easy last you a year, or you can split it with friends and get them to chip in. Since buying this stuff I will never, ever pay ridiculous shop prices again.