imo +1 for scrapebox fake pR cheker which is now my favorite for bulk PR checking anyway.
but
the underlying question is - ok so you've found yourself a "real" high PR blog, but what is the difference between a PR4 worth $30 and a PR4 worth $1000 (excluding site revenue)?
and these days that is what really matters. i can "make" a PR4 in a few weeks nowadays...but what makes it worth a shit?