I just heard back from the casting guys, and the figures would be, at best, extremely difficult to produce in resin. These figures were designed to be done as injection molded plastic in China, so converting them to be spin-cast will take some work. They are putting together prices for me right now, and if those look good, we'll go ahead and see if we can get them done in metal.
In the future, the figures may be able to be designed so that resin is a possibility.
Price wise, it really wouldn't make too much of a difference anyway. The figures would probably be about the same... especially at the low volume that we would be making.