Well if you do the straw bale way, Instead of hitting up the hardware store and spend like 6 bucks a bale. Just got to any farms that you may have around your area, and just go up to there house and see if they have an straw for sale.
More then likely they will or if they dont they will know who does.

AND if you get it from a farmer you will only spen about 3 bucks for straw.

So check that out, the straw bales will deffently stop your arrows.