Probably unlikely, as the airline I'm at now (DAL) doesn't fly to all of the same airports as Ryanair or Easyjet.

But, when I was at the cargo carrier, you have to factor in the ground transportation to the whole equation. A 100-200 euro taxi ride from your hotel to the airport in the boonies kills the savings in the fare. Also - the low fares (1 pound, etc) fares are bought up far ahead of departure. The cargo company I flew for didn't know they needed airline tickets until the day before - or the same day, so many of those low fares weren't available. When I was airlined from A to B, it was on carriers such as British Airways, Thai, or Kuwaiti Air.

Also, the company would have to pay to check two bags, overnight bag and flight kit, which further cuts into any savings from the legacy carriers.