Like several others have mentioned, the best prices I've found on the softer non-tox shot has been in the form of loaded shells, usually 3 1/2" 12 gauge, or 10 gauge loads. I think the guys with those guns are happy enough with steel.
One concern if you run in to some of the very earliest bismuth loads is that they can be very brittle. A buddy of mine found out the hard way. Couldn't kill anything with them. When he eventually patterned some loads on paper, all he saw were black splotches. The box was a gray traditional 25 shell box that had sat on a gunshop shelve for several years. At some point, and I don't know when, they started adding tin to make the pellets more ductile. I've been very happy with bismuth loads from more recent output (green boxes, 10 shells per box).
One thing I've wondered about is whether the tungsten matrix or tungsten polymer loads are abrasive enough to warrant some extra precautions while reloading: a longer shot cup or a sleeve. Anyone looked in to this, or have more info?