So... really... you want it plain and simple.
Ah! You're asking for a Margherita then. Excellent. Well, if you take the 9" you can get a second one for half price. Or opt for a 12" for £7 but that's collect only. Unless you take The Works (tm) and then use the customise option to delete the peppers, olives, pepperoni etc. That could work out a little more though.