Other things being equal, they consume the same WATTS, which is what you pay for. 10 amps at 120 volts is 1200 watts. 5 amps at 240 is also 1200 watts. There are some advantages like for the same KW energy usage, you could use smaller wires, and since given same wire size, the higher amp unit would produce more heat ( I-squared_R) , and heat is wasted energy.
In the case of a window air conditioner, none of the above would be anything to lose sleep over.