Comfortably the cheapest, by a fair bit, that I can find for these two Scalextric sets. Elsewhere they are retailing for between £50 and £90.
Scalextric Inner City Speed Set
Scalextric Inner City Speed Set includes 2 Mini Cooper Cars, track with crossover, mains transformer and hand throttles.
Scalextric Speed Rivals Set
A great introduction to the world of Scalextric racing, featuring a figure-of-eight track with exciting crossover section.
The two 'Super Resistant' single seater racers are tough enough for full impact racing. The cars feature easy change pick-ups and the Magnatraction system to help them stay on the circuit.