I believe it's mostly a difference in finishes and minor parts (grips, sights, hammer, etc.); the innards should all be the same. It seems the .40 cal's are a little bigger/more robust (or at least heavier). A highly-polished gun (the "Standard" model) can reasonably be expected to be more expensive because of the additional hand-labor required. The walnut grips are traditional and pretty, but the plastic ones are much more ergonomic; and there are aftermarket wood grips that are even better. In any case, the Hi-Power is very slim for a double-stack gun ... and, being single-action, the reach to the trigger is minimal.