Soldier Blade is overrated, in my humble opinion. Good game, but Final Soldier is better. Why is the game overpriced? The same reason 90% of the rest of the American games are overpriced..... SB arguably has the best graphics of the series, but the weapon selection is a bit bland compared to FS and for the fourth game in a series, it really offers nothing new in the gameplay department.
I'd give it a rank of "solid," but I can't agree with others that it is the "best HuCard shooter." There are plenty of better cart-based shooters in the American library, and if we're counting the JP library as well, it probably wouldn't even make the top 5.