Isn't LS more of an EZY than LS?
EZY&LS: BCN
FR: GRO/REU
EZY&LS: AMS
FR: EIN
EZY and LS seem to serve the 'bigger' airports and base alot of their UK flights around the Spanish and Portugese sun-spots (AGP, ALC, FAO etc) whereas FR tend to use sun-spots such as Seville and Granada.
This is why we see a price difference:
EZY&LS: 20.99 GBP single (inc. taxes)
FR: 5 GBP (inc. taxes)