That's cool that you got them. I'm sure they'll be fun.
I'm barely informed at all, but the Japanese version of the show has had like 37-ish seasons, and each season has a different theme/aesthetic, and then there are variations of the characters within particular seasons. Like the season it was samurai rangers, there was regular samurai and mega samurai, and maybe more. There's just a ton of possible designs for each ranger. I don't know how many versions the Figuarts has done or is doing, but at how much these cost I'd imagine it could be hard for someone to just collect all these.
And the first season that hit the US was like the 16th series in Japan. Or something. Maybe someone who knows the wizzbizz can educate me.