They do 4 x 2ml samples for £5 delivered, via that link. It was an offer that popped up on Facebook. I received mine today: pineapple sauvage, purple gourmand, man in the mirror and narcotic noir (which smells like Britney Spears according to my wife).
Like you say, you can get 4 x 5ml samples for £25 and choose which ones you get.