The costs you speak of are relative, not fixed things. At the moment you are correct, but neglect to factor in the cost of acquiring the natural gas itself.  On site hydrogen reforming may be cheap, but the cost of delivering liquid hydrogen fuel is nearly the same as electrolysis.  Furthermore, no one has mentioned the costs of electrolysis using hydro-electric power, tidal, or wind.  In an ocean based plant using the sea water (a natural electrolyte which electrolyzes better than pure water) with tidal power, wind, and solar operating in tandem the costs would be VERY cheap.  And, the costs must be considered to be amortized over the lifetime of the plant.  Solar panels, windmills, and tidal generators have a one-time, fixed cost, and then they run basically for free until repairs become necessary.  

Statistics designed to make electrolysis of water look expensive are easy to fabricate.  However, you must show where these supposed costs are coming from.  In addition, the people who claim that electrolysis of water is as polluting as hydrocracking always assume that the electricity must be generated by the burning of fossil fuels such as coal or natural gas.  People conveniently overlook all the factors that don't suit their basic belief or economic interest.  Take away the subsidies to the oil and gas industries, factor in the public health costs, add the money spent on security, and the transportation costs to bring it to market... and then see if it is truly cheaper.