I'm having difficulty understanding the serf option. You pay £30 but the option is not to buy the whole set? So, you get no models up to that amount? That means, if I buy the four items at £7.20 = £28.80 I get 10% off even though I've already paid £30 up front. Does that mean I've paid £55.92 for items selling at £28.80?
Sorry if I misunderstood the option.