Hm, neat. I see what you did there. The Parsename had me all sorts of scragged up until I broke it down and figured out what you were avoiding with it. Neat trick. Not much else you can do with that for speed, though, you're dealing with significant string manipulation at that point, not numerics.

For regional settings, afaik and what I can find in BoL, region will affect your default collations and default datetime components, but not directly selected money styles.