Aside from the power supply, I honestly don't think there's 30 dollars worth or parts in those boxes. :(
If it were men, I'd just buy 4 x rechargeable 9v batteries along with a current regulator diode and something together for much less money.
PS. the electrodes seems nice however, though I'd I think I read somewhere that the electrical field doesn't form around a plate as well as it does with round wire electrodes.