The turret finder is nice, but a lot more expensive than the 35mm finder. I got one of the latter with my J-12---I don't remember if it was a package deal or what---and it's a good-quality, usable finder.
-NT
The (ie most) turret(s) has (have) a frame you can see out side of and does other focal lengths as well, so yes well expensive but not if you are going for a system and spend time looking for individual finders in gbag.