Just bought a pair of cromo egg beaters in my local Halfords for £17.50, not sure if this was a mistake at store and neither was the assistant so bargain was had. If like me you've been ponderering a change of diet from spuds to eggs this seems a silly cheap way to trial, check the "boutique" cabinet at your halfords.
FWIW I guess £17.50 would be about right, they are the most basic of the eggbeater range. Great pedals, I used them for years before going back to Shimano. I still prefer Crank Bros but the longevity (or lack of it) of their bearings is awful IME.