Hydrogen is much cheaper than helium, and you can make it at home rather than going to the Airgas store if you take the appropriate precautions. This is not a tutorial on my recommendations for how to set up the reaction, but do take care to prevent the reactions from thermally running away. Both of these reactions produce heat, and they progress more quickly as they heat up. Surrounding the reaction vessel in a water bath can help retard the reaction which has the additional benefit of reducing the water vapor in the resulting hydrogen.
The reactant calculations assume that the reactions are 100% efficient and that the resulting hydrogen has no water vapor in it. The molarity of hardware store muriatic acid is assumed to be 11.6 M.