Hi! I'm the guy who sells genuine service kits for Nissan Micras (ebay item number 270560511750)
Although people will probably think I am biased, I have to say many of these cheaper kits on ebay are made up from the cheapest available parts (usually from China)
A service kit contains parts which affect the life of your engine (filters) and reliability and performance (spark plugs) so cutting corners can be a false economy.
My kits are twice the price but are made up of genuine Nissan parts from a real Nissan dealer. For the sake of saving £15 you have to ask yourself if you are servicing your car for the sake of it or are you servicing it because it will live longer and perform more efficiently?